Number of results: 10,054

**algebra/math**

Suppose that people's heights (in centimeters) are normally distributed, with a mean of 165 and a standard deviation of 6. We find the heights of 40 people. (a) How many would you expect to be between 158 and 172 cm tall?

*August 27, 2011 by Anonymous*

**statistics**

1) A scale measuring prejudice has been administered to a large sample of respondents. The distribution of scores is approximately normal with a mean of 31 and a standard deviation of 5. What percentage of sample had scores below 20?

*September 27, 2011 by Mich*

**Statistics**

Scores on the Stanford-Binet Intelligence scale have a mean of 100 and a standard deviation of 16, and are presumed to be normally distributed. A person who scores 68 on this scale has what percentile rank within the population?

*October 17, 2011 by Jen*

**statistics**

The average middle-distance runner at a local high school runs the mile in 4.5 minutes, with a standard deviation of 0.3 minute. Find the percentage of a runners that will run the mile in less than 4 minutes?

*March 5, 2012 by dw*

**statistics**

The mean life of a set of batteries in a T83 calculator is 525 with a standard deviation of 35 hours assume normal distribution is normal whats is the probability that set will last for more the 540 hrs

*March 17, 2012 by mike*

**statistics**

The average electric bill in a residential area is $72 for the month of May. The standard deviation is $6. If the amounts of electric bills are normally distributed, find the probability that the mean of the bill for 15 residents will be less thatn $75

*May 5, 2012 by Bunny*

**Statics**

An automotive engineer wants to use 64 test runs to estimate the true mean tire stopping distance. The standard deviation is assumed to be 32 feet. What is the probability that the error of the estimate will be more than 4 feet?

*December 2, 2012 by Heather*

**Statistics**

Consider a basketball game where a player throws from the free throw line. Her success rate is 65%. If she throws 10 times in a game determine the following:The mean and standard deviation of this binomial distribution.

*March 2, 2013 by Sue*

**math check**

Consider the following set of data. Pairs 1 2 3 4 5 Sample A 2 8 7 9 2 Sample B 7 8 1 1 8 Find the standard deviation sd of the paired differences. (Give your answer correct to two decimal places.) My answer was 5.00.

*June 22, 2013 by Tommy8*

**mah statistics**

the following table gives the number of camcorders sold on a given day in an electronics store X: 0, 1, 2, 3, 4, 5, 5, P(x) 0.5, .12, .23, .3, .16, .1, .04 find the mean, variance, and standard deviation of the daily sales of camcorders in the store.

*December 12, 2013 by james ohara*

**Statistics**

The weights of male babies less than 2 months old in the United States is normally distributed with a mean of 11.5 pounds and a standard deviation of 2.7 pounds. Find the 80th percentile score for these weights.

*February 25, 2014 by Jeri Jackson*

**math probability**

Daytime high temperatures in New York in February are normally distributed with an average of 30.2º and a standard deviation of 8.5º. Estimate the probability that the temperature on a given day in February is 39º or higher.

*March 4, 2014 by Jamar*

**statistics**

A food manufacturer samples 7 bags of pretzels off the assembly line and weighs their contents. If the sample mean is 14.2 oz and the sample standard deviation is 0.60 oz., find the 95% confidence interval of the true mean.

*March 16, 2014 by Anonymous*

**STATISTICS(PLEASE READ)**

Find warranty period (in days) for a washing machine whos average (mean) life is 6 years and standard deviation of 2.5 years. Assume 365 days in a year.

*January 22, 2015 by colleen*

**please answer statistics**

Find warranty period (in days) for a washing machine whos average (mean) life is 6 years and standard deviation of 2.5 years. Assume 365 days in a year.

*January 22, 2015 by lorin*

**stats**

glucose level in patients free of diabetes are assumed to follow a normal distribution with a mean of 120 and a standard deviation of 16. (20 pts) What proportion of patients has glucose levels exceeding 115?

*July 26, 2015 by genia*

**math**

Suppose the scores of students on an exam are normally distributed with a mean of 393 and a standard deviation of 57. According to the empirical rule, what percentage of students scored between 279 and 507 on the exam

*October 3, 2016 by betsy*

**Statistics**

Scores on an SAT test have a mean of μ = 1026 and a standard deviation of σ = 209. Compute the margin of error of the sample mean for a random sample of 100 students.

*October 9, 2016 by Allie*

**math**

Find the z-score for the given raw score, mean, and standard deviation. Assume a normal probability distribution. Raw score = 15, ì = 16 , and ó = 2

*November 1, 2009 by katie*

**statistics**

a math test has a mean of 43 and a standard deviation of 17.0. find the corrresponding z scores for a test score of 13 and a test score of 59. show work

*October 11, 2010 by Anonymous*

**statistics**

A normal population has a mean of 21 and a standard deviation of 5. Compute the z value associated with 24 What proportion of the population is between 21 and 24? What proportion of the population is less than 18?

*November 21, 2010 by Barbara*

**algebra**

The diameter of an electric cable is normally distributed, with a mean of 0.8 inch and a standard deviation of 0.01 inch. What is the probability that the diameter will exceed 0.81 inch

*March 8, 2012 by mj*

**Statistics**

The diameter of an electric cable is normally distributed, with a mean of 0.7 inch and a standard deviation of 0.01 inch. What is the probability that the diameter will exceed 0.71 inch?

*June 1, 2013 by Anonymous*

**statistics**

The diameter of an electric cable is normally distributed, with a mean of 0.7 inch and a standard deviation of 0.01 inch. What is the probability that the diameter will exceed 0.71 inch?

*June 1, 2013 by Anonymous*

**UNM**

Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. 42% of the students weights are above what kilograms?

*February 10, 2014 by Anonymous*

**UNM**

Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. 45% of the students weights are above what kilograms?

*February 10, 2014 by Anonymous*

**math**

The diameter of an electric cable is normally distributed, with a mean of 0.6 inch and a standard deviation of 0.01 inch. What is the probability that the diameter will exceed 0.61 inch?

*March 4, 2014 by lorine*

**math**

A class of 43 students took an exam. They had a mean average of 67 and a standard deviation of 7. a) how many students got a c b) how many students got a b c) what is a scoree needed to get an a is a) 4 b) 1 c) 90

*November 16, 2008 by joe-c*

**Statistics**

If a completion time for a task is normally distributed with a mean of 15 seconds and a standard deviation of 2.5 seconds, what is the probability of getting a time less than 9.7 seconds?

*July 25, 2010 by Edward*

**statistics**

a math test has a mean of 43 and a standard deviation of 17.0. find the corresponding z scores for a test score of 13 and a test score of 59. show all work.

*October 11, 2010 by mary*

**Math**

The volumes of soda in quart soda bottles are normally distributed with a mean of 32.3 oz and a standard deviation of 1.2 oz. What percentage of bottles contain less than 32 oz of soda?

*December 11, 2010 by Deb*

**Statistics**

Assuming that the heights of college women are normally distributed with mean 66 inches and standard deviation 2 inches, what percentage of women are shorter than 72 inches?

*May 2, 2013 by RainbowGlitter*

**Math**

The mean time to complete a certain stat quiz is 25 minutes, with a standard deviation of 5 minutes. Find the probability of a student taking. 1.) less than 15 minutes. 2.) Between 15 and 25 minutes. 3.)more than 25 minutes.

*April 14, 2013 by John*

**math**

Find the z-score for the given raw score, mean, and standard deviation. Assume a normal probability distribution. Raw score = 124, μ = 98, and o = 17 A) 0.65 B) -1.53 C) -0.65 D) 1.53

*November 18, 2009 by JEN*

**college, statistics**

a math test has a mean of 43 and a standard deviation 0f 17.0. find the corresponding z scores for. show all work. I. a test score of 13 II. a test score of 59

*October 11, 2010 by mary*

**Statistics**

Suppose that weights are bell shaped with a mean of 120 pounds and a standard deviation of 10 pounds. What percentage of weights is between 110 and 130 pounds

*May 14, 2011 by Robby*

**statistics**

The heights of 500 boys are measured and found to be normally distrubuted with a mean of 66 inches and a standard deviation of 2 inches.About how many boys are taller than 68 inches?

*December 12, 2011 by Anonymous*

**statistics**

ER promises you will be seen in 10 minutes. the standard deviation is 2 minutes. chance someone will wait more than 13 minutes. i don't know what to do without a population size or sample size

*April 3, 2013 by K*

**UNM**

Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. What percent of students have weights greater than 80.1 kilograms?

*February 10, 2014 by Anonymous*

**STATS**

Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. B. What percent of students have weights greater than 80.1 kilograms?

*February 10, 2014 by Tracy*

**statistics**

1)Let X have a normal distribution with mean 6 and standard deviation 3. a) What is the probability that X > 8.7 2)What is the probability that X<0? 3)What is the probability that |X-6| > 1.9 ? I have got so far: P(Z > 0.9) but I do not know where to go from here! ...

*October 7, 2012 by rachel*

**Statistic 103**

The average teachers salary in Connecticut( ranked first among states) is $57,337. suppose that the distribution of salaries is normal with a standard deviation of $7500. What is the probability that a randomaly selected teacher makes less than $52,000 per year?

*April 13, 2011 by Jennifer*

**Business Statistics**

A random sample of six CEOs reported how many times per year they play tennis. The data follows. 3 41 96 32 52 19 Assuming the number of games played is normally distributed and the population standard deviation σ = 10, a 95% confidence interval for μ is:

*June 14, 2013 by me*

**math**

what is the z-score for the given raw score, mean and standard deviation, assume a normal probability dist. raw score=66,u=60, and 0=6 u and o are those wierd symbols is the answer 1, 10, 6, or 66

*August 8, 2009 by Diana*

**Algebra 2: Prob and Stats**

The numbers of cookies in a shipment of bags are normally distributed, with a mean of 64 and a standard deviation of 4. What percent of bags of cookies will contain between 60 and 68 cookies? * 50% * 13.5% * 68% * 34%

*May 24, 2010 by Skye*

**statistics**

The lengths of pregnancies are normally distributed with a mean of 268 days and a standard deviation of 15 days. Out of 50 pregnancies, how many would you expect to last less than 250 days?

*December 8, 2010 by Terry*

**statistics**

Percentage grades in a large physics class follow a normal distribution with mean 58. It is known that 3% of students receive grades less than 39.2. What is the standard deviation of grades in the class?

*March 4, 2013 by Anonymous*

**Statistics**

The distribution of heights of adult American men is approximately normal with a mean of 68 inches and a standard deviation of 2 inches. What percent of mean are at least 72 inches tall?

*July 4, 2013 by Anonymous*

**math**

The distribution of heights of adult American men is approximately normal with a mean of 68 inches and a standard deviation of 2 inches. What percent of mean are at least 72 inches tall? Thanks!!

*July 5, 2013 by Anonymous*

**statistics**

Height of children in kindergarten described by normal mode with mean 39.2 inches and standard deviation of 1.9 inches. What percent of children can expect to be less than 38 inches tall?

*February 1, 2014 by Ann*

**quanitative methods**

The time required to complete a project is known to be normally distributed with a mean of 44 weeks and a standard deviation of 8 weeks. (a) What is the probability that the project is finished in 40 weeks or fewer?

*February 5, 2014 by Anonymous*

**statistics**

If 1,000 students take a test that has a mean of 40 minutes, a standard deviation of 8 minutes, and is normally distributed, how many would you expect would finish in between 24 and 48 minutes?

*August 6, 2014 by pablo*

**Math**

Suppose you have a mean standardized score of 1500 points with a standard deviation of 150 points. This data is normally distributed. What is the z-score of 1600 points? 0.75 0.5 0.67 0.32

*May 31, 2015 by Destiny*

**Algebra 2**

The heights of 200 kindergarten students are normally distributed with a mean of 40 and a standard deviation of 1.8 inches. Approximately how many students have a height between 37.3 inches and 44.5 inches?

*January 18, 2017 by Dee*

**statistics**

at a bank, account balances are nomrally distribued with a mean of $637.52 and standard deviation of $623.16. What is the probability that a simple randon same of 400 accounts has mean that exceeds $1650.00? show me steps and calculations i urgently need help

*January 23, 2008 by son*

**statistics**

Please let me know if I solved this right The lifetime of television produced by the Hishobi Company are normally distributed with a mean of 75 months and a standard deviation of 8 months. If the manufacturer wants to have to replace only 1% of its televisions, what should its...

*February 11, 2011 by Holly*

**statistics**

1. The average number of articles produced by two machines per day is 200 and 250 with standard deviation 20 and 25 respectively on the basis of records of 25 days production. Can you regard both the machines equally efficient at 1% level of significance?

*March 5, 2012 by lokesh*

**statistics**

A balloon mannufacturer kows that historically her company has produced 614 balloons per day (standard deviation =36) she has changed the process and wants to know wheathert he new process is increased the number of ballons made. the sample mean is 620. 0.5, n=16

*March 5, 2013 by kim*

**statistics**

The serum cholesterol levels for men in in one age group are normally distributed with mean of 178.1 and standard deviation of 40.8. All units are in mg/100ml. Find two levels that cut off the top 10% and the bottom 10 % from the distribution of x.

*October 30, 2013 by Amy*

**statistics**

Assume that thermometer readings are normally distributed with a mean of 0.0 and a standard deviation of 1,00. the thermometer is randomly selected and tested. For the case below, draw a sketch , and find the probability of the reading The given values in Celsius degrees) ...

*November 22, 2013 by judy*

**Basic Statistics**

A researcher is interested in estimating the average salary of police officers in a large city. She wants to be 95% confident that her estimate is correct. If the standard deviation is $1050,how large a sample is needed to get the desired information and to be accurate within...

*October 15, 2014 by John*

**state**

A machine put the juice in the bottle with normal distribution with mean is equal to 50 cl, with the standard deviation 5 cl. Test was done to see if the claim is right. A sample of 100 bottles were tested. They got the average content of 48.9 cl. At ∝ =0.05, can the ...

*December 11, 2015 by iram*

**Algebra**

I do not understand this homework at all. Any help or elaboration would be greatly appreciated. Thanks. 100 juniors at Southwest High took the SAT test. The scores were distributed normally with a mean of 22 and a standard deviation of 3. Label the mean and three standard ...

*April 12, 2016 by Kesha*

**maths**

The data in table below gives marks for an exam of a particular tutors students in 2005 and 2006. Year students marks on the exam 2005 75 86 91 65 83 75 88 90 66 99 2006 60 78 75 98 79 90 80 88 81 90 from the following choose two options which are true about the table above. a...

*May 19, 2007 by angel*

**Algebra 2**

Suppose you did a survey of male shoes size and the mean of that survey was size 10 with a standard deviation of 1.5. What is the z-score of a size of 7.5?

*June 7, 2011 by Adam*

**Math**

Suppose you did a survey of male shoes size and the mean of that survey was size 10 with a standard deviation of 1.5. What is the z-score of a size of 7.5?

*June 7, 2011 by Wyeth*

**Stats**

A Math test has a mean of 51 and standard deviation of 5.0. Find the corresponding z scores for: I. a test score of 64 II. a test score of 47

*October 15, 2011 by Jennifer*

**probability**

normally distributed with a mean of 40 minutes and a standard deviation of 5 minutes. What is the probability that it will take more than 40 minutes? Answer

*January 24, 2012 by Dillon*

**Help please! Math**

A car is designed to last an average of 12 years with a standard deviation of 0.8 years. What is the probability that a car will last less than 10 years?

*January 12, 2014 by Katalina*

**Statistics**

A criminologist is studying school violence, she selects a random sample of 25 adolescents aged 12 to 15 from a local middle school and asks the following,"How many times within the past school year have you been physically assaulted at school? She calculated the following ...

*February 27, 2015 by Elena*

**Stats**

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

*March 24, 2009 by Sally*

**bus. stats**

Given that math SAT scores are normally distributed (follow the empirical rule) m=500 Standard deviation=100 what is the math SAT score for someone who is in the 80th percentile of his or her class.

*March 3, 2010 by mike*

**bus. stats**

Given that math SAT scores are normally distributed (follow the empirical rule) m=500 Standard deviation=100 what is the math SAT score for someone who is in the 80th percentile of his or her class.

*March 3, 2010 by mike*

**business research**

The standard deviation of the sample is 0.4. Over the last 10 years, the average GPA has been 3.0. Is the GPA of this year’s students significantly different from the long-run average? At what alpha level would it be significant

*March 8, 2010 by joi*

**Statistics**

19. George got 70% on an economics exam where the mean was 55% and the variance was 9. If a professor wishes to change the distribution of marks so that they have a mean of 70% and a standard deviation of 5, what will George’s new mark be? a) 95% b) 85% c) 90% d) Over 100% ...

*October 23, 2010 by Rhea*

**Quantitative methods**

the mean and standard deviation of the grades of 500 students who took an maths exam were 69 and 7 respectively. if the grades have a bell shaped distribution, how many of these students received a grade of more than 83 marks?

*April 7, 2011 by lisa*

**Quantitative methods**

the mean and standard deviation of the grades of 500 students who took an maths exam were 69 and 7 respectively. if the grades have a bell shaped distribution, how many of these students received a grade of more than 83 marks?

*April 7, 2011 by lisa*

**mathematical modeling**

Use the 68-95-99.7 rule to solve: The amount of Jen's monthly phone bill is normally distributed with a mean of $48 and a standard deviation of $6. Fill in the blanks. 95% of her phone bills are between $_____ and $_____.

*March 27, 2012 by Jeremiah*

**economics**

the average tax charge is $95. Assuming a normal distribution as a standard deviation of $10, use the approximate areas beneath the normal curve to answer what proportion of tax prep fees were exactly $100?

*December 15, 2012 by Anonymous*

**statistics**

Your samle is normally distributed with a mean age of 57. The standard deviation iin this sample is 5 years.The 2000 census shows your sample is older than a randomly selected national sample. The median agein your sample is?

*June 3, 2013 by statistics*

**Math IV**

what is the margin of error for a simple random sample of 900 people with a standard deviation of 13.5 at 95% level of confidence How do you write this question in the right formula, please? I believe I can calculate the problem, I don't know how to write it. 900 2.5 and 1.96

*August 20, 2014 by Darryl*

**Statistics**

Below are the numbers of games played in the World Series from 1903 to 2012. Find the mean, variance and standard deviation. Games played Probability 4 0.186 5 0.231 6 0.203 7 0.341 8 0.039

*February 20, 2015 by E.man*

**MATH**

A food snack manufacturer samples 15 bags of pretzels off the assembly line and weighed their contents.If the sample mean is 10.0 and the sample standard deviation is 0.15, find the 95% confidence interval of the true mean.

*April 16, 2015 by GRACE*

**math**

Adult IQ scores are normally distributed with mean 100 and standard deviation 15. Find the IQ score that separates the adults with the highest 3% of IQ scores from the rest of the adults. Round your answer to the nearest whole number.

*March 31, 2016 by anon*

**stats**

Using the following data set a. Calculate the mean, mode, median, standard deviation, minimum, maximum and range b. Draw the histogram of the data set. Use 100 as bin width

*April 16, 2016 by ABDULA YUSUF*

**stats**

Using the following data set a. Calculate the mean, mode, median, standard deviation, minimum, maximum and range. b. Draw the histogram of the data set. Use 100 as bin width.

*April 17, 2016 by Anonymous*

**Statistics**

Suppose a fair coin is tossed five times and let x be the number that turned up in those five times. **the mean and the standard deviation are respectively... a.) 0.5, 0.5 b.) 2.5, 0.5 c.) 2.5, 2.24 d.) 2.5, 1.12 **find P(x≥1) a.) 0.5 b.) 1.0 c.) 0.03 d.) 0.97 * i just ...

*May 30, 2016 by Caitlyn*

**Statistics**

From a sample with n equals=24, the mean number of televisions per household is 3 with a standard deviation of 1 television. Using Chebychev's Theorem, determine at least how many of the households have between 1 and 5 televisions.

*September 18, 2016 by Addison*

**Statistics**

suppose that 80% of all 18 year olds play basketball. if a sample size of 4 is taken, find the probability that the sample proportion lies within and including one standard deviation of the population proportion

*October 14, 2016 by Jay*

**statistics**

The mean rent of a 3-bedroom apartment in Orlando is $1200. You randomly select 12 apartments around town. The rents are normally distributed with a standard deviation of $75. What is the probability that the mean rent is more than $1000?

*November 13, 2016 by e*

**math**

2 51 45 58 41 44 37 38 40 44 45 40 59 45 44 34 44 43 48 32 38 1.Determine the mean of the data 2.Determine the standard deviation of the data

*May 19, 2013 by jacob*

**ap statistics**

What is the mean of the sample means? What is the standard deviation of the sample means?

*April 24, 2014 by emma*

**ap statistics**

What is the mean of the sample means? What is the standard deviation of the sample means?

*April 25, 2014 by emma*

**Algebra**

The mean is 18.1 the data set for 13 is -1.7 What is the standard deviation for this data set.

*July 27, 2015 by Malu*

**statistics**

The daily sales of a retail store are normally distributed with a standard deviation of $500. If the probability that sales will be less than $10,000 in any one day is 40%, what are the mean daily sales?

*April 23, 2013 by Anonymous*

**Statistics**

The daily sales of a retail store are normally distributed with a standard deviation of $500. If the probability that sales will be less than $10,000 in any one day is 40%, what are the mean daily sales?

*April 22, 2015 by Anonymous*

**Statistics**

ATM transaction times are normally distributed with a mean of 150 seconds and a standard deviation of 45 seconds. What is the probability a person takes less than 60 seconds to complete their transaction?

*February 19, 2016 by Anonymous*

**Stat**

The lengths of pregnancies in a small rural village are Normally distributed with a mean of 268 days and a standard deviation of 12 days. What percentage of pregnancies last beyond 290 days?

*February 13, 2017 by Vlad*

**stat**

The ministry of transport and communication is responsible for the enforcement of airline safety regulations and has become concerned about an apparent increase in accidents and near mishaps involving commercial aircraft. One area of concern is overloading due to passenger ...

*August 23, 2014 by LwEeNdO*

**Statistics**

It is known that the amount of time needed to change the oil in a car is normally distributed with a standard deviation of 5 minutes. A random sample of 100 oil changes yielded a sample mean of 22 minutes. Compute the 99% confidence interval estimate of the mean of the ...

*February 26, 2007 by Jason L*