Saturday

February 28, 2015

February 28, 2015

Number of results: 8,485

**statistics**

The life span of the battery pack is known to be Normally distributed with a mean of 250 hours and a standard deviation of 20 hours. How to find the percentage of the battery packs lasting more than 250 hrs.
*May 6, 2012 by noe*

**statistics**

The Intelligence Quotient (IQ) test scores for adults are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability we could select a sample of 50 adults and find the mean of this sample is between 95 and 105?
*November 11, 2012 by Trev*

**statistics**

The winning team's score in 11 high school basketball games were recorded. If the sample mean is 9.5 points and sample standard deviation is 0.25 points, what is the 98% confidence interval for the true population mean?
*November 24, 2012 by Christi*

**Steve help!**

10,000 students took a math test. If there average score was 40 with standard deviation of 10, how many students must have scored between 20 and 40 marks? 3,772 2,227 5,000 3,334 4,772
*November 28, 2012 by Tina*

**stats**

scores on a university examination are normally distributed with a mean of 68 and standard deviation of 9. What percetnage of students scores above 77? The answer is 16% according to the professor that is correct. But I don't understand how the professor got to that answer.
*March 14, 2013 by Anonymous*

**statistic**

The random variable x represents the number of boys in a family with three children. Assuming that births of boys and girls are equally likely, find the mean and standard deviation for the random variable x.
*August 20, 2013 by Kim*

**statistics**

A random sample of 100 students from a high school was selected. If a 98% confidence interval estimate for the mean age of students is calculated to be 14.2511 to 14.9489, then the standard deviation of the sample mean is?
*November 17, 2013 by zac*

**math**

A study of 60 bolts of carpet showed that their average length was 180 yards. The standard deviation of the population is 6 yards. Which of the following is the 99% confidence interval for the mean length per bolt of carpet?
*April 14, 2014 by hassan*

**math**

Studies shown that gasoline use or compact cars sold in the U.S. is normally distributed, with a mean of 25.5 mpg and standard deviation of 4.5 mpg. Find the range of mileage for the middle 60% of compact cars.
*November 18, 2014 by sarah*

**statistics**

In a population of exam scores, a score of x=88 corresponds to z=+2.00 and a score of x=79 corresponds to z=-1.00. Find the mean and standard deviation for the population.
*February 5, 2008 by Tegan*

**Math**

In a population of exam scores, a score of X=88 corresponds to z= +2.00 and a score of X=79 corresponds to z= -1.00. Find the mean and standard deviation for the population.
*September 25, 2009 by Jen*

**statistics**

In a population of exam scores, a score of X=88 corresponds to z= +2.00 and a score of X=79 corresponds to z= -1.00. Find the mean and standard deviation for the population.
*September 25, 2009 by Jen*

**AP Statistics**

if the probability of a dribbling drummer is .38, find the standard deviation of the dribbling drummers drumming for the twelve drummers drumming
*January 6, 2010 by Belle*

**statistics**

In a population of exam scores, a score of X = 48 corresponds to z = +1.00 and a score of X = 36 corresponds to z = -0.50. Find the mean and standard deviation of the population.
*March 17, 2010 by Teresa*

**Stats**

A loaf of bread is normally distributed with a mean of 22 ounces and a standard deviation of .5 ounces. What is the probability that a loaf of bread is < 20.75
*March 30, 2010 by Anonymous*

**statistics**

In a population of exam scores,a score of X= 48 corresponds to z= 1 and a score of X= 36 corresponds to z= -.50. Find the mean and standard deviation for the population?
*March 9, 2012 by Amy*

**Math**

On a recent math exam, Alex received a score of 92%. His z-score is positive 2. If the mean for the exam is 84, what is the standard deviation?
*April 16, 2013 by James Jones*

**Probability**

A department store has determined that 25% of all their sales are credit sales. A random sample of 75 sales is selected and the proportion of credit sales in the sample is computed. a) What is the probability that the same proportion will be greater than 0.34? In a random ...
*November 23, 2006 by Janice*

**Finite Math**

If the life in years, of a television set is normally distributed with a mean of 46 years and a standard deviation of 4 years, what should be the guarantee period if the company wants less than 3% of the television sets to fail while under warranty?
*February 13, 2010 by Maria*

**math**

The heights in inches of 18 randomly selected adult males in LA are listed as: 70, 69, 72, 57, 70, 66, 69, 73, 80, 68, 71, 68, 72, 67, 58, 74, 81, 72. Display the data in a stem-and-leaf plot. 1. Find the mean. 2. Find the median. 3. Find the mode. 4. Find the range. 5. Find ...
*May 19, 2010 by Bill*

**Statistics**

The heights in inches of 14 randomly selected adult males in LA are listed as: 71, 67, 70, 59, 71, 68, 67, 71, 80, 68, 74, 69, 72, 68. 1. Display the data in a stem-and-leaf plot. 2. Find the mean. 3. Find the median. 4. Find the mode. 5. Find the range. 6. Find the variance...
*September 20, 2010 by Shawna *

**Math: Statistics**

A study of elephants wishes to determine the average weight of a certain subspecies of elephants. The standard deviation of the population is 2,014 pounds. How many elephants need to be weighed so we can be 93% confident to be accurate within 325 pounds?
*November 17, 2010 by Anonymous*

**statistics**

A company that manufacturers bookcases finds that the average time it takes an employee to build a bookcase is 23 hours with a standard deviation of 8 hours. A random sample of 64 employees is taken. What is the likelihood that the sample mean will be 18 hours or more?
*March 6, 2012 by Diane*

**Math**

For a class test, the mean score was 65, the median score was 71 and sthe standard deviation of the scores was 7. The teacher decided to add 5 points to each score due to a grading error. Which of the folloiwng must be true for thenew scores? TH
*August 15, 2011 by Gail*

**statistics**

The heights in inches of 14 randomly selected adult males in LA are listed as: 71, 67, 70, 59, 71, 68, 67, 71, 80, 68, 74, 69, 72, 68. 1. Display the data in a stem-and-leaf plot. 2. Find the mean. 3. Find the median. 4. Find the mode. 5. Find the range. 6. Find the variance. ...
*November 13, 2011 by Anonymous*

**stats**

blood cholesterol level of all men age 20-24 follows N(188,41) where the units for the men and standard deviation are in mg/dl. what is the probability that the sample mean takes a value between 185 and 191 if we sample 1000 men
*October 12, 2012 by sam*

**statistics**

A group of 49 randomly selected construction workers has a mean age of 22.4 years with a standard deviation of 3.8. According to a recent survey, the mean age should be mu=21.9. Test this hypothesis by constructing a 98% confidence interval for the population mean.
*November 19, 2013 by Cheryl*

**statistics**

the average act score submitted to a certain university is 26. to be eligible for admission, a student must score in the top 6% of applicants. if the scores are normally distributed with a standard deviation of 2.4, what is the minimum score needed to be considered for admission?
*March 21, 2014 by roger*

**Statistics **

The life of a blood pressure monitor has a normal distribution with an average of 40 years and a standard deviation of one year. What should the warranty be to replace a malfunctioning monitor with - if the company does not want to replace more than 1% of all the monitor. ...
*June 6, 2014 by Ann*

**Math**

The weekly salaries of 100 recent graduates of a private women's college are normally distributed with a mean of $600 and a standard deviation of $80. Determine the interval about the sample mean that has a 1% level of confidence. Use t=2.58 I don't know. 600/sqrt100 60 80+-2....
*October 1, 2008 by Anonymous*

**Math**

The weekly salaries of 100 recent graduates of a private women's college are normally distributed with a mean of $600 and a standard deviation of $80. Determine the interval about the sample mean that has a 1% level of confidence. Use t=2.58 I don't know. 600/sqrt100 60 80+-2....
*October 1, 2008 by Anonymous*

**Statistics**

The amount of fill(weight of contents)put into a glass jar of spaghetti sauce is normally distributed with mean=850g and standard deviation=8g.the probability that a random sample of 24 jars has a mean weight greater than 848g is?need help
*March 23, 2011 by Joel*

**stats ( please check)**

6. X has a normal distribution with a mean of 80.0 and a standard deviation of 3.5. Find the following probabilities: (A) P(x < 77.0) (B) P(75.0 < x < 85.0) (C) P(x > 85.0) (Points : 6) I think I have the first two but I am stumped on the third one. Thank you for ...
*July 24, 2011 by Celest*

**statistics**

In a preliminary study, the sample standard deviation for the duration of a particular back pain suffered by patients was 18.0 months. How large a random sample is needed to construct a 90% confidence interval so that an estimate can be made within 2 months of the actual duratio
*August 2, 2011 by joe*

**statistics**

The SAT scores of a certain population of students are approximatley normally distributed with a mean and standard deviation of 1000 and 200 points, respectively. the probabilalty that a student selected at random from the population has an SAT score between 800 and 1200 is?
*February 28, 2013 by ken*

**math**

A sample of size 100 is chosen from a normally distributed mean,(µ) and standard deviation 60. A researcher has made the statement as follow to conclude that value of µ: " reject H0:µ= 80 and accept H1: µ < 80. if x̅ < 68 " a) if the significant level used is ∝...
*October 17, 2013 by sree*

**CRJ303-Statistics question**

Re-worded from the "Study Questions" part of Chapter 5 from this site: "Student Study Site for Essentials of Social Statistics for a Diverse Society" Please show the steps for each question "When the Scholastic Aptitude Test (SAT) - now known as the Scholastic Assessment Test...
*December 7, 2012 by Michael*

**statistics**

14.how would you describe this set of data? In other words, how would you describe the “average” score (mean, median or mode and why)? How would you describe the variability (range, standard deviation, or both, and why)? 3 3 3 4 3 2 4 2 3 4
*November 23, 2010 by Lola*

**Math**

*Sigh* Can someone explain to me how I would work thru this problem? An honest coin tossed n=3600 times. Let the random variable Y denote the number of tails tossed. (a) find the mean and the standard deviation of the distribution of the random variable Y (b) what are the ...
*October 5, 2006 by SherylA*

**statistics**

The average price for new mobile homes is known to be distributed with a standard deviation of 350. if a random sample of 49 homes resulted in a sample mean of 38500, obtain a 90% confidence interval on the population mean.
*March 26, 2009 by April*

**statistics**

Assume that blood pressure readings are normally distributed with a mean of 123 and a standard deviation of 9.6. If 144 people are randomly selected, find the probability that their mean blood pressure will be less than 125
*November 8, 2011 by Anonymous*

**statistics**

Determine the probability that a sample of 49 boxes will have a mean weight below 365grams. past records show that the population mean is 368 grams and the population standard deviation is 7. the probability will be between
*November 30, 2011 by wanda*

**Statistics**

The weights of trout in a certain river follow a normal distribution with mean 3 pounds and standard deviation 0.8 pounds. What proportion of trout weigh between 3.2 pounds and 4.8 pounds? a.) .3891 b.) .9972 c.) .9452 d.) .5865
*December 1, 2011 by Jay*

**statistics**

what happens to the width of our confidence interval for mu if we increase the sample size but keep the confidence level the same ? a. it increases b. it stays the same c. it decreases d. it depends on the sample mean and standard deviation
*December 6, 2011 by jen*

**Statistics**

suppose a random sample of 360 students is drawn form a population of students. Among sampled, the average IQ score is 12 with standard deviation of 3. What is the upper confidence limit of the 95% confidence interval of the population
*March 14, 2012 by Arona Basuti*

**Statistics**

The distribution of heights of women aged 20 to 29 is approximately Normal with mean 63.6 inches and standard deviation 3 inches. The height (± 0.1 inch) of the middle 68% of young women falls between a low of inches and a high of inches.
*September 4, 2012 by Stacie*

**statistics**

supposed that the average weight loss for someone on a diet is 15 pounds with the standard deviation of 4 pounds. a sample of 18 adults enrolled a sswp have a mean weight loss of 15.83. using 0.01 level of significance.
*October 2, 2012 by jericho*

**statistics**

5. What happens to the width of our confidence interval for m if we increase the sample size but keep the confidence level the same? A) It increases. B) It decreases. C) It stays the same. D) It depends on the sample mean and standard deviation.
*May 8, 2013 by ali awan*

**statistics**

Assume that blood pressure readings are normally distributed with a mean of 123 and a standard deviation of 9.6. If 144 people are randomly selected, find the probability that their mean blood pressure will be less than 125.
*October 14, 2013 by florence *

**statisticss**

The time taken by a man to deliver milk is normally distributed with, mean 12 minutes and standard deviation 2 minutes. He delivers milk everyday estimate the probability that he takes. (a) longer than 17 minutes (b) between 9 and 13 minutes
*July 8, 2014 by Heidi*

**Probability**

Please help.. Find the probability of getting 2 hearts if the cards are drawn from a regular deck and the first card is not replaced. A true/false quiz consists of twenty questions. If a student answers the twenty questions by making random guesses, what is the probability of ...
*December 10, 2006 by Mary*

**math**

It is equally probable that stock A will have a +10% or -10% rate of return The only other possibility is that it will return 0%.The probability of 0% is twice that for a return of +10%. What is the expected return and Standard deviation of the return for stock A?
*September 24, 2014 by Anonymous*

**Chemistry**

When 0.312g of glucose was burned in a bomb calorimeter (heat capacity 641 J/K) the temperature rose by 7.739 K. Calculate the standard enthalpy of combustion and the standard internal energy of combustion. I've calculated the standard enthalpy but am unsure of how to go about...
*September 25, 2012 by Kalli *

**Statistics**

30 randomly selected cans of Coke are measured for the amount of cola in ounces. The sample values have a mean of 12.18 ounces and a standard deviation of 0.118 ounces. The 99% confidence interval is ( ounces, ounces). Round each result to two decimal places.
*November 9, 2013 by Katie*

**math**

The average selling price of homes in a certain city is $356,300. Assume the variable is normally distributed with a standard deviation of $64,600. If 396 homes are for sale, how many homes will sell for more than $325,000? (Round up to the next whole number.)
*November 28, 2011 by Jennifer*

**statistics**

A company produces batteries whose lifetimes are normally distributed with a mean of 100 hours. It is known that 90% of the batteries last at least 40 hours. (i). Estimate the standard deviation lifetime. (3 marks) (ii). What percentage of batteries will not last 70 hours?
*April 26, 2013 by Ravi*

**Math - Pre-Algebra**

44) A financial institution wishes to estimate the mean balances owed by its credit card customers. The population standard deviation is estimated to be $300. If a 98 percent confidence interval is used and an interval of ±$75 is desired, how many cardholders should be sampled...
*August 30, 2010 by BC*

**math**

at one high school the mean time for running the 100-yard dash is 15.2 seconds with a standard deviation of 0.9 seconds. The times are very close approximated by a normal curve. Find the percent of times that are: between 15.2 and 16.1 seconds
*July 14, 2008 by Leanne*

**statistics**

The amount of snow fall falling in a certian mountain range is normally distributed with a mean of 83 inches, and a standard deviation of 16 inches. What is the probability that the mean annual snowfall during 64 randomly picked years will exceed 85.8 inches?
*March 4, 2009 by kasey*

**math**

Find the z-score for the given raw score, mean, and standard deviation. Assume a normal probability distribution score = 15, ě = 16 , and ó = 2 Could you show me how to do this. My instructor has tried but I just don't understand how to do it and I have several questions to ...
*August 23, 2009 by sam*

**Statistics**

A lorry carries heavy cartons of goods. The weights of theses cartons are distributed about a mean of 100 kg and with a standard deviation of 7 kg. Find how many cartons the lorry can carry so that the probability of the total load exceeding 4500 kg is less than 0.5.
*April 18, 2012 by Sniper619*

**Q. Research**

3. Bob takes an online IQ test and finds that his IQ according to the test is 134. Assuming that the mean IQ is 100, the standard deviation is 15, and the distribution of IQ scores is normal, what proportion of the population would score higher than Bob? Lower than Bob?
*December 9, 2012 by Maurice*

**statistic**

A grain mill manufactures 100-pound bags of flour for sale in restaurant supply warehouses. Historically, the weights of bags of flour manufactured at the mill were normally distributed with a mean of 100 pounds and a standard deviation of 15 pounds. a. What is the probability...
*December 6, 2012 by anonymous*

**Statistics 2**

The body temperature of healthy human beings can be assumed to have a normal distribution with mean and standard deviation . Body temperature measurements taken from a sample of 130 healthy individuals shows the sample mean temperature to be 98.249O F and ...
*December 16, 2013 by Steven *

**Statistics**

In Professor White’s statistics course the correlation between the students’ total scores before the final examination and their final examination scores is r = 0.9. The pre-exam totals for all students in the course have mean 275 and standard deviation 50. The final exam ...
*October 21, 2012 by Kevin*

**graduate statistics**

Do children from lower socioeconomic status (SES) neighborhoods have lower than average test-taking skills? A researcher administered a standard measure of test-taking skills to a randomly chosen child from a low SES neighborhood and found him to have a score of 38. The ...
*July 3, 2013 by Anonymous*

**math**

The weights of adult long-tongued fruit bats are known to be normally distributed with a mean of 20.22 grams and a standard deviation of 3.23 grams. What is the probability that a randomly selected bat will: a) weigh at most 15 grams? b) weigh less than 30 grams?
*March 21, 2012 by becky*

**Math**

The weights of adult long-tongued fruit bats are known to be normally distributed with a mean of 20.22 grams and a standard deviation of 3.23 grams. What is the probability that a randomly selected bat will: a) weigh at most 15 grams? b) weigh less than 30 grams?
*March 23, 2012 by Becky*

**calculus**

The salaries at a corporation are normally distributed with an average salary of $29,000 and a standard deviation of $4,000. Sixteen percent of the employees make more than Sara. What is Sara's salary? Round your answer to the nearest dollar.
*June 5, 2012 by Sam*

**statistics**

Ramdom sample of 41 car owners results in a mean of 7 years. Population standard deviation of 3.75 years. Find a 95% confidence interval for the true population mean..My answer is (5.9, 8.1) but having problems with margin of error
*December 8, 2012 by Anonymous*

**statistics**

assume that the volume of drink is normally distributed, with a mean of 2.0 liters and a standard deviation of 0.05 liter. Using the random sample of 45 bottles. The probability is 99% that the sample mean will contain at least how much soft drink?
*March 19, 2013 by virginia*

**statistics**

The test scores of students in a class test have a mean of 65 and with a standard deviation of 8. What is the probable percentage of students scored more than 70? Please check work 70-65/8 = .625 = .2357 = 1.-.2357 = .7643 ANSWER 76% ????
*February 10, 2014 by Anonymous*

**statistics**

You have a score on a national entrance exam of 95. What percentage of people in the population have a score that is lower than yours? (Assume the population mean is 75 and the standard deviation is 10. Use the table I passed out in class.)
*February 26, 2014 by Anonymous*

**statics**

The standard deviation of the lifetime of certain TV picture tubes is estimated as 150 hours. How much large a sample must be taken in order to be 99% confident that the error in the estimated means lifetime will not exceed 25 hours
*November 18, 2014 by aima*

**Please help me with statistics**

I was asked to: Calculate the d value or effect size for A but use this data instead. A. Group one 12 and group two 11 standard deviation 3 Can anyone please help me figure out how to find the d value. Any help would be great.
*November 20, 2014 by Jennifer*

**math 3**

a sample of restraunts in a city showed that the average cost of a glass of iced tea is $1.25 with a standard deviation of 7 cents. if a new restraunt charges a price for iced tea that has a z value of 1.25, then what is the teas actual cost
*November 20, 2014 by raven*

**famu**

Construct a 99% confidence interval for the population mean, ě. Assume the population has a normal distribution. A group of 19 randomly selected employees has a mean age of 22.4 years with a standard deviation of 3.8 years. Round to the nearest tenth.
*December 1, 2014 by Anonymous*

**statistics**

2. The new Twinkle bulb has a standard deviation hours. A random sample of 77 light bulbs is selected from inventory. The sample mean was found to be 492 hours. a. Find the margin of error E for a 90% confidence interval. Round your answer to the nearest hundredths.
*May 2, 2010 by stefanie*

**college**

Essentials of statistics is the subject and the question is: The population of IQ scores forms a normal distribution with a mean of u=100 and a standard deviation of sigma=15. What is the probability of obtaining a sample mean greater than M=105 for a random sample of n=36 ...
*July 31, 2010 by Jennifer*

**Math**

i have a question regarding statistics. i just don't know how to do it and would really appreciate if someone could tell how i can solve it. the question is; a) compute the mean and the standard deviation of the population? ive looked through all my notes and my textbook and i...
*November 21, 2010 by ash*

**statistics**

The diameter of small Nerf balls manufactured at a factory in China is expected to be approximately normally distributed with a mean of 5.2 inches and a standard deviation of .08 inch. Suppose a random sample of 20 balls is selected. Find the interval that contains 87% of the ...
*June 28, 2012 by Josh*

**statistics**

The scores on a test for a very large class is normally distributed with mean 64 points and standard deviation 6 points. The department decides to award A to the highest 5% scores. What is the minimum score to receive an A for the course? Round your answer (down) to nearest ...
*July 11, 2012 by Anonymous*

**statistics**

Random samples of size n are selected from a normal population whose standard deviation is know to be 2. Suppose you want 90% of the area under the sampling distribution of x bar to lie within + or - 1 unit of a population mean u. Find the minimum sample size n that satisfies ...
*November 23, 2012 by joe*

**Stat Help Please**

Yearly stock returns on India's Sensex Index are well described by a Normal model with a mean of 18.36% and a standard deviation of 14.65%. give the stock return cutoff for the middle 30% of all years. I used TI-83 Calc. for these. Can someone check them? Thank you! Q1=InvNorm...
*March 10, 2013 by Taylor*

**Statistics**

1.The average number of acts of physical violence in a random sample of 150 TV movies was 4.5 acts with a standard deviation of 0.75. At the 95% confidence interval level, what is your estimation of the mean range of all movies shown in the television? Explain the result in ...
*October 4, 2013 by Chris*

**statistics**

A large number of applicants for admission to graduate study in business are given an aptitude test with a resulting mean score of 460 with a standard deviation of 80. The top 2.5 percent of the applicants would have a score of at what? A. 606 B. 617 C. 600 D. 646
*April 11, 2014 by Jill*

**Math statistics**

How large a sample should be taken if the population mean is to be estimated with 95% confidence to within $69? The population has a standard deviation of $892. (Round you answer up to the nearest whole number.) You may need to use the appropriate table in Appendix B to answer...
*June 8, 2014 by hanjay*

**Statistics**

Let's pretend the Work variable is normally distributed, with a mean/median/mode value of 22 and a standard deviation of 17. Based on these numbers, we can say that approximately 68 percent of SOC 390 students work between ______ and ______ hours per week.
*September 8, 2014 by Chris*

**Math- Statistics**

A random sample of size 36 is to be selected from a population that has a mean μ = 50 and a standard deviation σ of 10. * a. This sample of 36 has a mean value of , which belongs to a sampling distribution. Find the shape of this sampling distribution. * b. Find the ...
*February 8, 2011 by Tammy*

**statistics**

The scores on the final exam in a course have approximately a bell-shaped distribution. The mean score was 72, the highest score was 99, and the lowest score was 41. Use the value of the range (58) to estimate the value of the standard deviation. (Round your answer to the ...
*September 21, 2011 by Chris*

**statistics**

11. A local health care company wants to estimate the mean weekly elder day care cost. A sample of 10 facilities shows a mean of $250 per week with a standard deviation of $25. What is the 90 percent confidence interval for the population mean?
*June 18, 2012 by tristen*

**Statics**

A power company takes a random sample of its delinquent account files. For 400 accounts, the average delinquent amount was $239.30 with a standard deviation of $14.52. With 99% probability, determine the maximum error of the estimate for the mean of all the delinquent accounts.
*December 1, 2012 by Heather*

**Statistics**

Bob takes an online IQ test adn finds that his IQ according to the test is 134. Assuming that the mean IQ is 100, the standard deviation is 15, and the distribution of IQ scores is normal, what proportion of the poulation would score higher than Bob? Lower than Bob?
*August 11, 2013 by Opal*

**Statistics**

A university has 1,000 computers available for students to use. Each computer has a 250-gigabyte hard drive. The university wants to estimate the space occupied on the hard drives. A random sample of 100 computers showed a mean of 115 gigabytes used with a standard deviation ...
*October 27, 2013 by Shelby*

**Statistics**

Assume that the sample is taken from a large population and the correction factor can be ignored. The average teacher's salary is $43152. Suppose that the distribution is normal with standard deviation equal to $7000. If we sample 100 teachers' salaries, what is the ...
*February 3, 2012 by Renita*

**statistics**

I cant figure this out!!! The income of trainees at a local mill are normally distributed with a mean of $1100 and a standard deviation of $150. If a sample of 100 trainees is selected, what is the probability that the sample mean will be less than $1075 month?
*September 13, 2008 by Denim*

**Statistics**

Two problems: 1. Find D sub 3 of the following data set: 60, 40, 26, 33, 23, 53, 36, 23, 28, 12, 30, 47 2. Find P sub 26 of the following 25 scores: 38.5, 41.5, 52, 52.5, 61, 63, 63.5, 68, 69, 69, 78.5, 79, 80, 83, 87, 88.5, 88.5, 91, 91.5, 92, 92.5, 94, 94, 97, 97 I have a ...
*June 24, 2009 by Amy*

**statistics**

the average of final exam is 64, the standard deviation is 7. If the teacher set a rule that 1/4 of students who receive the poor grades should stay after class. lower than what mark should the students stay in school? does anyone know how to solve this?
*January 3, 2010 by K.T*

**statistics**

Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4 There are 200 students in a sample. How many of these students will have scores that fall under the score of 41?
*September 9, 2011 by Jean*

**Statistics**

Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4. There are 200 students in a sample. How many of these students will have scores that fall under the score of 41?
*September 9, 2011 by Jean*

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