Wednesday

November 25, 2015
Number of results: 9,126

**Stastics**

Bank of Connecticut estimated that balance on credit cards have follows Normal Distribution mean $845 with standard deviation $270. Calculate probability that balance on a single credit card is greater than $750
*March 7, 2010 by Mary *

**statistics**

At a ski area in Vermont, the daytime high temperature is normally distributed during January, with a mean of 22°F and a standard deviation of 10°F. You are planning to snowboard there this January. What is the probability that you will encounter daytime highs of a) 42°F or ...
*April 23, 2010 by Rose*

**statistics**

At a ski area in Vermont, the daytime high temperature is normally distributed during January, with a mean of 22°F and a standard deviation of 10°F. You are planning to snowboard there this January. What is the probability that you will encounter daytime highs of a) 42°F or ...
*April 29, 2010 by john*

**college**

Suppose that, for a certain exam, a teacher grades on a curve. It is known that the grades follow a normal distribution with a mean of 70 and a standard deviation of 7. There are 45 students in the class. How many students should receive an A? Please, round your answer to the ...
*December 22, 2010 by Anonymous*

**statistics**

we are interested in testing at level of significance alpha =10 whether the population mean is different than 15. a random sample of size 25 is taken with a mean of 13.9. assume standard deviation is 2 and normally distributed population. find the values for zcrit
*December 6, 2011 by jen*

**statistics**

In a survey of 400 college students, 40 were left-handed. Treating the sample as if it were random and using 0.015 as the standard deviation of the sampling distribution of the sample proportion, what is the lower bound of a 95% confidence interval for the population proportion?
*May 18, 2012 by D*

**statistics college**

suppose we have a set of blood pressure set with a mean of 120 systolic and a sample standard deviation of 20 points assume a normal distribution of what two values should 95% of all systolic bp lie
*May 22, 2012 by melba*

**Stat**

The salaries at a corporation are normally distributed with an average salary of $29,000 and a standard deviation of $4,000. What is the probability that an employee will have a salary between $22,520 and $23,480? Enter your answer rounded to exactly 4 decimal places.
*June 5, 2012 by Sam*

**statistics**

A class test resulted in a mean score of 60% and a standard deviation of 15%. You scored 75%. Assuming the scores follow a normal distribution, and there are 200 in the class, how many students scored better than you? Give your answer to the nearest whole number.
*August 30, 2012 by rebecca*

**statistics**

The average homicide rate for the cities and towns in a state is 10 per 100,000 population with a standard deviation of 2. If the variable is normally distributed, what is the probability that a randomly selected town will have a homicide rate greater than 14?
*March 24, 2013 by brittany*

**Statistics**

A simple random sample of 10 households, the number of TV's that each household had is as follows: 1, 3, 1, 2, 0, 2, 1, 1, 1, 5 Assume that it is reasonable to believe that the population is approximately normal and the population standard deviation is 0.56. What is the lower ...
*June 26, 2013 by Anonymous*

**Math/Statistics**

A statistics teacher believes that the final exam grade for her elementary stats class have a normal distribution with a mean of 82 and a standard deviation on 8. Find the score which separates the top 10% of the scores from the lowest 90% of the scores.
*August 11, 2013 by Sean*

**Statistics**

The distribution of heights of women aged 20 to 29 is approximately normal with a mean of 2.8 inches and standard deviation of 2.8 inches. The height (+/- 0.1 inch) of the middle 99.7% falls between a low of ?? inches and a high of ?? inches. Please help on how I set this up ...
*September 10, 2015 by Angel*

**Statistics**

The grades in the final exam of a random sample of 25 students produce a standard deviation, s = 9.5. a) Construct a 90% confidence interval estimate for the population variance, . b) Can we infer at 10% level of significance that the population variance is significantly ...
*November 25, 2014 by Kendra*

**College of education ekiadolor Benin **

The scores of an achievement test given to 100,000 students are normally distributed with mean 500 and standard deviation 100.what should the score of a student be to place him or her among the 10% of the students?
*June 14, 2015 by Biriemi powei*

**Stats**

workers at a large toxic cleanup project are concerned that their white blood cell counts may have been reduced. The white blood cell count in the general population is known to have a mean of 7500 cells/mL with a standard deviation of 1750cells/mL a)what is the probability of...
*May 23, 2015 by Ish*

**statistics**

–/3 points Notes Question: TanColM7 8.6.003. TKK Products manufactures electric light bulbs in the 50-, 60-, 75-, and 100-watt range. Laboratory tests show that the lives of these light bulbs are normally distributed with a mean of 774 hr and standard deviation of 68 hr. Find ...
*October 15, 2010 by br0Ok3*

**statistics**

given the group of numbers: 8,9,10,10,10,11,11,11,12,13. which of the following are the same? a)range and mean,b)mode and median, c)standard deviation and mode d)mean and median, e)none
*April 22, 2011 by BV*

**Statistics **

True or false? If the original x distribution has a relatively small standard deviation, the confidence interval for will be relatively short. Answer True False
*July 7, 2012 by Desperate *

**Rioja**

A normally distributed population with 200 elements has a mean of 60 and a standard deviation of 10. The probability that the mean of a sample of 25 elements taken from this population will be smaller than 56 is:
*February 22, 2013 by Laws*

**statistics**

A teacher finds that the test scores of a group of 40 students have a mean of 75 and a standard deviation of 10. If Anne has a test score of 88, what is Anne’s z-score?
*November 14, 2013 by latisha*

**Probability/Statistics**

Assume 20 oz. cola bottles are filled so that the mean amount of liquid contained in the bottle is 20 oz and the standard deviation is .12 oz. If a bottle is randomly selected, find the probability that the number of ounces in that bottle is greater than 20.21 oz.
*June 21, 2008 by thomas*

**statistics**

Bob is a salesman. He receives $20 for each sales plus a fixed salary of $100 per week. Bob's average weekly sales is 70 units with a standard deviation of 15. Bob works 45 weeks a year.
*September 18, 2011 by tuyet*

**Statistics**

If red has a probability of occurrence of .70 and black has a probability of occurrence of .30 and they are the only choices what is the probability that you pick the right color 10 out of 10 times and what is the standard deviation. I keep getting (.70*.50) + (.30*.50) = .50...
*February 11, 2012 by Joe D.*

**statistics**

Suppose the final exam scores in a large class is symmetric mound shaped with a mean of 70 points and standard deviation of 10 points. The percentage of students in the class who receive more than 60 points is approximately
*February 17, 2012 by Anonymous*

**Math**

An aptitude test has a mean of 300 and a standard deviation of 40. The test scores are normally distributed. If 1000 people take the test, find the number of people who will score between 280 and 360.
*July 12, 2014 by Shelagh*

**Statistics**

the age of costumers for a particular retail store follows a normal distribution with a mean of 37.5 years and a standard deviation of 7.6 years. what is the probability that the next costumer who enters the store will be less than 42 years old?
*March 15, 2015 by Leo Elvis*

**Statistics**

Assuming that the heights of college women are normally distributed with mean 62 inches and standard deviation 3.5 inches, what percentage of women are between 58.5 inches and 72.5 inches? (Points: 5) 34.1% 84.0% 15.7% 13.6% 97.6%
*June 20, 2010 by alex*

**statistics**

Heights of young adult US women are approximately normal with mean 64" and standard deviation 2.7". What proportion of all US young adult women are taller than 6 feet?
*September 9, 2010 by Anonymous*

**Physics**

Can someone please tell me how to calculate the standard deviation of the following values? 0.985 0.985 1.005 1.455 1.035 And please for the following numbers too 1.47 1.52 1.50 1.45 1.39
*February 8, 2011 by Abi*

**math**

i took the sat and recieved a score of 488 on the math section. the average score was 445 with a standard deviation of 110. where does my score fit in the sample and what is the z score?
*July 29, 2011 by patricia*

**statistics**

Heights of young adult U.S. women are approximately normal with mean 64" and standard deviation 2.7". What proportion of all U.S. young adult women are taller than 6 feet?
*January 23, 2012 by Ashley*

**Statistics**

The annual precipitation for one city is normally distributed with a mean of 72 inches and a standard deviation of 3.5 inches. In 95% of the years, the precipitation in this city is between___ and ___
*July 23, 2012 by Marc*

**Math - Please help**

The population standard deviation of people who shop online is 3.1. If you want to be 75% confident that the sample mean is within 10% of the population mean, how many people must be surveyed?
*December 4, 2012 by Alley*

**algebra 2**

The average score on a standardized test is 750 points with a standard deviation of 50 points. What is the probability that a student scores more than 700 on the standardized test?
*September 23, 2014 by Anonymous*

**Statistics**

A simple random sample of 60 items resulted in a sample mean of 64. The population standard deviation is 16. a. Compute the 95% confidence interval for the population mean (to 1 decimal).
*October 28, 2014 by Anonymous*

**Statistics and probability**

A psychologist tested the IQ in a sample of 36 children. Their mean IQ was 104. What is the probability of getting an IQ score of 104 or higher? The mean is 100, and the standard deviation is 15
*November 8, 2015 by Echell*

**Quantitative Analysis**

Under conditions where a large sample is used in experimental research, and "power" of a statistical test is maximized, it is possible to have statistically significant results, yet a fairly small...? A. Ethical concern B. Effect size C. Set of assumptions D. Standard Deviation
*November 8, 2013 by Stacie*

**Salary Related - Stats question**

The monthly starting salaries of students who receive engineering degrees have a standard deviation of $600. What sample size should be selected so that there is 0.95 probability of estimating the mean monthly income within $150 or less?
*November 25, 2009 by Desire*

**Statistics**

A bank wishes to estimate the mean balances owed by their MasterCard customers within $75. The population standard deviation is estimated to be $300. If a 98% confidence interval is used, how many cardholders should be sample. Please provide sample size formula in calcutions.
*January 26, 2010 by Bryant*

**stats**

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? A...
*July 7, 2010 by Ali*

**Statistics**

When fifteen vehicles were observed at random for their speeds (in M.P.H.) on a freeway, the following data were obtained. 61 53 57 55 62 58 60 54 62 60 59 66 55 54 63 Suppose that from past experience it may be assumed that vehicle speed is normally distributed with standard ...
*April 29, 2012 by Jennifer*

**Statistics**

When fifteen vehicles were observed at random for their speeds (in M.P.H.) on a freeway, the following data were obtained. 61 53 57 55 62 58 60 54 62 60 59 66 55 54 63 Suppose that from past experience it may be assumed that vehicle speed is normally distributed with standard ...
*April 30, 2012 by Beth*

**statistics**

a. Compute the mean, median, and mode. b. Compute the variance, standard deviation, range, coefficient of variation, and Z scores. Are there any outliers? Explain. c. Are the data skewed? If so, how? d. Based on the results of (a) through (c), what conclusions can you reach ...
*December 23, 2012 by lou*

**Statistics**

The mean monthly rent for a one-bedroom apartment without a doorman in Manhattan is $2,636. Assume the standard deviation is $500. A real estate firm samples 100 apartments. What is the probability that the average rent of the sample is more than $2,680?
*June 20, 2013 by Anonymous*

**Math**

assume that the speed of automobiles on an expressway during rush hour is normally distributed with a mean of 62 mph and standard deviation of 5 mph. What percent of cars are traveling faster than 62 mph? How would I work this problem out?? Thanks for any and all help anyone ...
*February 20, 2010 by Bianca*

**Statistics**

A survey was conducted to determine the number of hours people listen to the radio. While most of the listening is in the car, it turns out that the mean is 2.5 hours with a standard deviation of 0.75 hours. Find the probability that the sum of 80 values is greater than 190.
*May 11, 2015 by Jake*

**Math**

The MPG for a certain compact car is normally distributed with a mean of 31 and a standard deviation of 0.8. what is the probability that the MPG for a randomly selected compact car would be less than 32?
*March 25, 2009 by Nate*

**Statistics**

Assuming that the heights of college women are normally distributed with mean 62 inches and standard deviation 3.5 inches, what percentage of women are between 58.5 inches and 72.5 inches? 34.1% 84.0% 15.7% my answer was 13.6 13.6% is this correct 97.6%
*June 20, 2010 by Jack*

**Statistics**

The weight of a product is normally distributed with a standard deviation of .8 ounces. What should the average weight be if the production manager wants no more than 5% of the products to weigh more than 5.3 ounces?
*October 6, 2010 by Beverley*

**math**

If you charge care for dogs 100 dollars plus an annual rate of 30. And cats 120 and an annual rate of 35 dollars, what is the difference of the standard deviation of the variables?
*December 3, 2010 by jhenssine*

**Statistics**

The null hypothesis,H0:u=48,was tested against the alternative hypothesis,H1:u>48.A sample of 75 resulted in a calculated p-value of 0.102.if standard deviation=3.5,the value of the sample mean is?need help
*March 23, 2011 by Joel*

**stats**

The weight of a product is normally distributed with a standard deviation of .8 ounces. What should the average weight be if the production manager wants no more than 1% of the products to weigh more than 7.3 ounces?
*June 14, 2011 by jenny*

**statistics**

The average score on a standardized test is 500 points with a standard deviation of 50 points. What is the probability that a student scores between 450 and 600 on the standardized test?
*July 21, 2011 by tom*

**statistics**

A normal distribution has a mean of µ = 100 with standard deviation = 20. If one score is randomly selected from this distribution, what is the probability that the score will have a value between X = 80 and X = 100?
*March 7, 2012 by Asia*

**statistics**

Given the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it between 50 feet and 60 feet?
*October 19, 2012 by Alex*

**Stats**

students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54. Treating this class as the population, what percent of students study more than 12 hours a week
*December 16, 2012 by Anonymous*

**statistics**

the probability that a football game will go into overtime is 17%. In 240 randomly selected football games, what is the mean and the standard deviation of the number that went into overtime
*June 23, 2013 by erin*

**Stats**

A random sample of size 100 is drawn from a population with a standard deviation of 10. If only 5% of the time a sample mean greater than 20 is obtained, the mean of the population is ______.
*December 13, 2013 by Matthew*

**STATS **

Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. Using the 68-95-99.7 rule, what is the lower bound for the weight of the top 2.5% of students?
*February 11, 2014 by Tracy *

**Statistics**

the average numbers of hours a cat sleep is approximately normally distributed with a mean of 15 hours and a standard deviation of 1.7 hours; what percentage of cats sleep between 13 and 18 hours
*April 27, 2014 by Belinda*

**algebra 2**

A newspaper claims that 52% of voters will vote for a particular candidate in an upcoming election. A random survey of 1000 voters shows that 48% will vote for that candidate, with a standard deviation of 3%.
*August 1, 2014 by george*

**stats**

The probability that a football game will go into overtime is 18%. In 140 randomly selected football games, what is the mean and the standard deviation of the number that went into overtime?
*October 21, 2014 by bob*

**Algebra 1**

A teacher graded the tests for each of her students. She calculated a mean grade of 80 and a standard deviation of 3. One of her students, Katrina, had a z-score of 2. What grade did Katrina get on the test?
*May 10, 2015 by Jacob*

**math**

Hi, How do I find the coefficient of variation? I found the sample variance and the standard deviation for the problem I'm trying to solve, but I can't find the coefficient of the variation
*May 3, 2009 by Stella*

**math**

Hi, How do I find the coefficient of variation? I found the sample variance and the standard deviation for the problem I'm trying to solve, but I can't find the coefficient of the variation
*May 3, 2009 by Stella*

**statistics**

Suppose a random sample of 36 is selected from a population with a standard deviation of 12. If the sample mean is 98, the 99% confidence interval to estimate the population mean is
*April 25, 2011 by mona*

**statistics**

If you have a population mean of 50 and a population standard deviation of 5 and you select a sample size of 100, what is the probability that the sample mean is between 47 and 49.5?
*April 27, 2011 by tom*

**math **

the rate of return for an investment can be described by a normal distribution with mean 22% and standard deviation 3%. what is the probability that the rate of return for the investment will be at least 15%?
*April 27, 2011 by Carola *

**statistics**

Bob scores 610 on his SAT's. If the mean score is 580 and the standard deviation is 115, what percentile is Bob's SAT score?
*May 21, 2012 by jordan*

**stats**

Joes test score was 450(1 standard deviation below the population mean550) A good guess for Joes test score is
*February 8, 2015 by ben*

**Statistics**

If the average home cost $100,000, with a standard deviation of $15,000, what would a home on the 20th percentile rank cost?
*April 3, 2015 by Jan*

**STAT- important**

What is the difference between normal distribution and approximate normally. Correct me if im wrong but I think the parameters of Normal is X~Normal (mu, standard deviation) but then approx. normal is X~Normal (mu, variation) im just really confused when you use each and such.
*December 18, 2014 by Sarah*

**statistics**

Assume the body weight of healthy fifth graders is normally distributed with a mean of 98.3 lbs and a standard deviation of 4.12 lbs. If you have a body weight of 89.3, what is your percentile score?
*July 8, 2010 by Ab*

**Business Statistic**

X f(x) 0 .25 1 .20 2 .15 3 .30 4 .10 Is it prpbsbility distribution valid? Explain and list the requirement for a valid probability distribution Calculate the expected value x Calulate the variance of x calculate the standard deviation of x
*October 16, 2010 by Laverne *

**nba stats help!!**

The weight of a product is normally distributed with a standard deviation of .8 ounces. What should the average weight be if the production manager wants no more than 1% of the products to weigh more than 7.3 ounces?
*June 15, 2011 by jenny*

**Statistics**

The actual weights of bag of pet food are normally distributed.The mean of the weights is 50.0 lb,with a standard deviation of 0.2 lb. A)About what percent of bags of pet food weigh less than 49.8 lb?
*June 4, 2012 by Anonymous*

**STATISTICS**

The height of PU men are normally distributed with mean 65 in. and standard deviation 5.3 in. find the probability of finding: a. A men selected is at least 75 in. tall? b. A man selected is no less than 58 in. tall?
*September 30, 2012 by JOE*

**Statics**

Assume that the population is normal. A sample of size 100 is taken. The resultant sample data has a mean of 48 and a standard deviation of 15. Construct the 99% confidence interval for the population mean.
*December 2, 2012 by Heather*

**Statistics**

A random sample of 60 riders waited in line a mean time of 42 minutes with standard deviation 12 minutes. Find a 90% confidence interval for the populationmean waiting time in line
*March 21, 2013 by Lost37*

**Math**

The inner diameter of a piston is normally distributed with mean of 10 cm and standard deviation 0.03cm a)below what value of inner diameter will fall fifteen percent of the piston rings?
*April 7, 2013 by Kira*

**Statistics**

he Oil Price Information Center reports the mean price per gallon of regular gasoline is $ 3.79 with a population standard deviation of $ 0.18. Assume a random sample of 40 gasoline stations is selected and their mean cost for regular gasoline is computed. 1. What is the ...
*September 26, 2010 by John*

**basic statistics for the behavioral sciences**

on a standard test of motor coordination, a sports psychologist found that the population of a average bowlers had a mean scores of 24,with a standard deviation of 6. she tested a random sample of 30 bowling alley and found a sample mean of 26, a second random sample of 30 ...
*September 12, 2011 by jan*

**science**

i need help with standard deviation and erro bars on graph, if i want to talk about my graph and mention the erro bars and what it means how do i do that?
*April 16, 2010 by piper*

**statistics**

the lenght of a species of fish is normally distributed with a mean of 24.3 inches and a standard deviation of 1.8 inches. What is the lenght that is exceeded by 30%of these fish
*June 19, 2012 by Anonymous*

**prob and stats**

–/3 points Notes Question: TanColM7 8.6.003. TKK Products manufactures electric light bulbs in the 50-, 60-, 75-, and 100-watt range. Laboratory tests show that the lives of these light bulbs are normally distributed with a mean of 774 hr and standard deviation of 68 hr. Find ...
*October 15, 2010 by br0Ok3*

**Statistics**

A telephone company receives 3 calls every minute on an average. If an operator has a watch that is not very accurate and which has a normal distribution with mean of 1 minute and standard deviation of 5 seconds, what is the probability that he measures 5 calls in a minute?
*February 4, 2011 by Georgina Hughes*

**statistics**

A study is discussed the purity of oxygen from a certain supplier. Assume that the mean was 99.61 with a standard deviation of 0.08. Assume that the distribution of purity was normal. Below what purity value would you expect to represent the smallest 25% of the population?
*December 16, 2011 by shasha*

**Probability and Statistics**

A marine biologist has determined that the weight of a full weight of 2000pounds and a standard deviation of 500 pounds. Determine the probability that the average weight of the next five sharks captured will be less than 2100lbs.
*April 29, 2012 by Kim*

**Statistics**

A random sample of customer incomes yields a mean income of $35000 with a standard deviation of $4500. Assume that the distribution of the incomes in normal. What income range would include 90% of the most popular incomes?
*August 2, 2012 by Danielle*

**statistics**

Suppose that the heights of female adults in the US are normally distributed with a mean (µ) of 65.4 inches and a standard deviation (σ) of 2.8 inches. Let X denote the height of a randomly chosen adult female. Find the probability that X is between 66 and 70 inches:
*March 15, 2013 by Lori*

**Statistics**

The age of customers for a particular retail store follows a normal distribution with a mean of 37.5 years and a standard deviation of7.6 years.What is the probability that the next customer who enters the store will be less than 42 years old?
*January 3, 2015 by Leslie Meagan*

**Elementary Statistics **

The diameters of pencils produced by a certain machine are normally distributed with a mean of 0.39 inches and a standard deviation of 0.04 inches. If 500 pencils are selected how many would you expect to have a diameter more than 0.33 inches?
*July 20, 2015 by Lizzy*

**Statistics**

The Wechsler Adult Intelligence Scale (WAIS) is a common "IQ test" for adults. The distribution of WAIS scores for persons over 16 yrs of age is approximately Normal with mean (100) and Standard Deviation 15, (a) Whatis the probability that a random chosen individual has a ...
*December 5, 2006 by Jason*

**math**

The FunTime Amusement park customer load during the summer follows a normal distribution with mean 450 and standard deviation 80. Determine the probability that the number of customers on any given day during the summer will be less than 420.
*September 29, 2009 by Matt*

**Math**

Need help with word problem. In the life, inyears of a television set with a mean of 20 years and a standard deviation of 1.8 years, what should be the guarantee period if the sompany wants less than 1% of the tv sets to fail while under warranty? should I take the .1 - 20/1.8=
*March 1, 2010 by Veronice*

**statistics**

The typical amount of sleep per night for undergraduate college students has a bell shaped distribution with a mean of 7 and a standard deviation of 1.90 hours. Based on this distributional information we can conclude that at least 95 % of this population sleep ...
*September 27, 2013 by jennifer*

**Algebra II**

The grades on the last math exam had a mean of 88%. Assume the population of grades on math exams is known to be normally distributed with a standard deviation of 6. What percent of students earn a score between 72% and 90%? (5 points) 0.6255 0.5843 0.6754 0.5346
*May 23, 2014 by Pewdiepie*

**Stat**

Thirty randomly selected students took the calculus final. If the sample mean was 89 and the standard deviation was 6.2, construct a 99% confidence interval of the mean score of all students. Assume that the population has a normal distribution. what formula do i use????
*September 30, 2014 by Billy*

**six sigma**

If the mean value of the weight of a particular brand of dog food bag is 20.6 pounds and the standard deviation is 1.3, assume a normal distribution and calculate the percentage of bags that falls below the lower specification value of 19.7 pounds.
*November 26, 2014 by stansler*