Monday

January 23, 2017
**statistics**

Find sd. The differences between two sets of dependent data areÂ -8,Â 4,Â; -6,Â 10. Round to the nearest tenth. A.) 4.3 B.) 195.5 C.) 6.8 D.) 8.5

*Saturday, November 5, 2016 by janet*

**Statistics**

"Suppose two independent samples have been collected.Based on a sample of 26 from the first population, you observe 14 successes. The second sample of size 26 had 17 successes. What is the critical value for a 85% confidence interval that compares these two population ...

*Saturday, November 5, 2016 by Chris*

**Statistics**

A friend gives you the following Fs and decision made. Does the decision appear to be correct? Explain.Do NOT provide critical or table values as explanations. F(2, 63) = .10, not significant F(3, 85) = -1.70, not significant F(1, 120) = 64.32, not significant F(5, 70) = 1.00...

*Thursday, November 3, 2016 by Lizzy*

**statistics**

Despite he outrageous incomes of some, the mean income of all aging rock stars is relatively modest: $75,000 with a standard deviation of $2,000. On that scale, Chubby Checker, appears to do better than average: at most, only 6.25% of aging rockers make more than he does. what...

*Wednesday, November 2, 2016 by Anonymous*

**Statistics**

Suppose Cindy is taking a multiple-choice test where there are 5 possible answers on each question. If she guesses on all 8 questions, what is the probability that she gets: a.) exactly 3 correct. b.) at least 1 correct. c.) What is the mean? d.) What is the standard deviation?

*Wednesday, November 2, 2016 by Luna*

**statistics**

a social worker is involved in a study about family structure. She obtains information regarding the number of children per family for a certain community from the census data. Identify the random variable of interest, determine whether it is discrete or continuous, and list ...

*Tuesday, November 1, 2016 by Anonymous*

**AP Statistics**

The ages of the Oscar-winners for best actor and actress for the years 1970 through 1990 are given below: Women: 34,34,26,37,42,41,35,31,41,33,30,74,33,49,38,61,21,41,26,80,72 Men: 43,40,48,48,56,38,60,32,40,42,37,76,39,55,45,35,61,33,51,32,42 Use what you have ...

*Tuesday, November 1, 2016 by Nana*

**statistics**

Suppose that the mpg rating of Passengers Cars is a normally distributed random variable with a mean and a standard deviation of 33,8 mpg and 3,5 mpg. Question : an automobiles manufacturer wants to build a new Passenger car with an mpg rating that improves upon 99% of ...

*Tuesday, November 1, 2016 by ggerrlo*

**Statistics**

Your pocket contains 2 quarters and 2 Nickels. You randomly pick one of the coins and without replacing it you pick a second coin. Are the events, Q1 = First pick was a quarter Q2 = Second pick was a quarter a) Independent? b) What is the probability of getting a quarter both ...

*Tuesday, November 1, 2016 by Anonymous*

**Statistics**

Three final candidates (Alex, Bo, and Chris) for a position happen to take different versions of the aptitude test. You are supposed to choose the one who performed best out of these three final candidates and the test results are as follows: Alex received 88 from the test ...

*Sunday, October 30, 2016 by Lacy*

**Statistics**

Please help me with this homework you roll two fair dice, a green one and a red one? (a) are the outcomes on the dice independent? (b)Find P(1 on green die and 2 on red die) (c)Find P(2 on green die and 1 on red die) (d)Find P(1 on green die and 2 on red die) or (2 on green ...

*Sunday, October 30, 2016 by Mary*

**Statistics**

you roll two fair dice, a green one and a red one? (a) are the outcomes on the dice independent? (b)Find P(1 on green die and 2 on red die) (c)Find P(2 on green die and 1 on red die) (d)Find P(1 on green die and 2 on red die) or (2 on green die and 1 on red die) a)yes b)p(1)*(...

*Sunday, October 30, 2016 by John*

**Statistics**

The Citiburg Parks Department has just installed 1100 new lightbulbs with an expected mean lifespan of 64 months and a lifespan standard deviation of 8 months. Assuming normally distributed bulb failure, how many bulbs will need to be replaced after 49 months? Round your ...

*Saturday, October 29, 2016 by Jen*

**Statistics**

The Townville Parks Department has just installed 1900 new lightbulbs with an expected mean lifespan of 75 months and a lifespan standard deviation of 12 months. Assuming normally distributed bulb failure, how many bulbs will need to be replaced after 53 months? Round your ...

*Saturday, October 29, 2016 by Jen*

**statistics**

Suppose the average weight for population of men is 178 pounds. You draw a random sample of 10 men and record the following weights: 150, 145, 180, 200, 175, 190, 142, 175, 240, 150. Calculate the sampling error.

*Thursday, October 27, 2016 by Bob*

**STATISTICS**

A3. A Retailing Entrepreneur sells sophisticated running shoes whose weights are assumed to be normally distributed with a mean of 12 grammes and a standard deviation of 0.5 grammes. (a) What is the probability that a shoe weighs more than 13 grammes? [3] (b) What must the ...

*Thursday, October 27, 2016 by ISRAEL*

**STATISTICS**

A2. Reviewed statistics indicated that there is an average of five thefts per day from a large supermarket operating from 08 00 to 19 00 six days a week. Find the probability that there (a) are no thefts in a week. [2] (b) will be ten thefts in any given day. [4] (c) are four ...

*Thursday, October 27, 2016 by MOSES*

**STATISTICS**

Miss Dombo, a Ticketing Manager with an Airline flying international routes, has realised that not all passengers show up for their reserved seat. It is clear to her that each passengerâ€™s behaviour is independent of the other. Having fixed the chances of a ...

*Thursday, October 27, 2016 by JANE*

**statistics**

In studying the responses to a multiple-choice test question,the following sample data were obtained. At the .05 significance level, test the claim that the responses occur with the same frequency. show work for test statistic & p. response a b c d e/ 12 15 16 18 19 my answer ...

*Wednesday, October 26, 2016 by Dhelp*

**Statistics**

The Villopolis Parks Department has just installed 1900 new lightbulbs with an expected mean lifespan of 66 months and a lifespan standard deviation of 6 months. Assuming normally distributed bulb failure, how many bulbs will need to be replaced after 56 months?

*Wednesday, October 26, 2016 by Jourdan*

**Statistics**

You are interested in estimating the mean of a population. you plan to take a random sample from the population and use the samples mean as an estimate of population mean. Assuming that the population from which you select your sample is normal, which of the statements about ...

*Tuesday, October 25, 2016 by Winston*

**Statistics**

The following simple random sample was selected from a normal distribution: 4, 6, 3, 5, 9, and 3. a. Construct a 90% confidence interval for the population mean μ.

*Tuesday, October 25, 2016 by tae*

**Statistics**

The playing time X of classical CDs has the normal distribution with mean 54 and standard deviation 5; the N(54, 5) distribution. What is the relative frequency of classical CDs with playing time X between 49 and 69 minutes?

*Tuesday, October 25, 2016 by Jasel*

**Statistics**

A VP of manufacturing claims that more than 3% of items produced using a certain assembly line are defective. A random sample of 400 items is selected. At the 10% level of significance, which of the following would be part of the standardized decision rule? - Conclude H0 if TS...

*Tuesday, October 25, 2016 by AL*

**Statistics**

In a distribution where the mean is to the right of the median, the histogram of the distribution will probably: a. have a longer tail on the right side b. show a uniform distribution c. be symmetric d. be bi-modal

*Tuesday, October 25, 2016 by Lea*

**Statistics**

Scores on the 1995 SAT verbal aptitude test among Kentucky high school seniors were normally distributed with an average of 420 and the SD of 80. Scores on the 1995 SAT quantitative aptitude test among Kentucky high school seniors were normally distributed with an average of ...

*Tuesday, October 25, 2016 by Madison*

**Statistics Probability**

A jar contains 5 red marbles, numbered 1 to 5, and 11 blue marbles numbered 1 to 11. a) A marble is chosen at random. If you're told the marble is red, what is the probability that it has the number 2 on it? b)The first marble is replaced, and another marble is chosen at ...

*Monday, October 24, 2016 by Jesus*

**STATISTICS**

Suppose that a researcher is interested in estimating the mean systolic blood pressure, , of executives of major corporations. He plans to use the blood pressures of a random sample of executives of major corporations to estimate . Assuming that the standard deviation of the ...

*Monday, October 24, 2016 by RILEY*

**STATISTICS**

A study of college football games shows that the number of holding penalties assessed has a mean of penalties per game and a standard deviation of penalties per game. What is the probability that, for a sample of college games to be played next week, the mean number of holding...

*Monday, October 24, 2016 by RILEY*

**statistics**

The current rate of success is 70% for 200 students. When the new test is implemented, the rate increases to 85% for the 50 students who pass the test and are allowed into the program. Is this difference significant?

*Sunday, October 23, 2016 by pamela*

**Statistics**

Assume a study of 500 randomly selected school bus routes revealed 480 arrived on time. Is it significant for a school bus to arrive late?

*Sunday, October 23, 2016 by Tracy*

**Statistics**

A dice rolling just once What is probability of given the face is odd, it is a 1?

*Sunday, October 23, 2016 by Rashad Suleymanli*

**Statistics**

Write an inequality that represents all of the data values X, that fall between the values of the mean +/- the standard deviation

*Friday, October 21, 2016 by Mary*

**Health!**

Statistics of Suicide regarding Antisocial Personality Disorder

*Friday, October 21, 2016 by J*

**science**

identify the best way to display statistics in a research report

*Friday, October 21, 2016 by luma*

**math**

How many paths spell STATISTICS using Pascal's triangle? S T T A A A T T T T I I I S S T I I C C C S S Thanks in advance

*Wednesday, October 19, 2016 by Jenna*

**statistics**

A naturalist leads whale watch trips every morning in March. The number of whales seen has a Poisson distribution with a mean of 2.1 Find the probability that on a randomly selected trip, the number of whales seen is 3. Round to four decimal places.

*Tuesday, October 18, 2016 by anonymous*

**statistics**

An unfair coin has a probability of coming up heads of 0.55 the coin is tossed 4 times. What is the probability that it lands heads at least once?

*Monday, October 17, 2016 by gio*

**Statistics**

A tobacco company claims that the nicotine content of its "light" cigarettes has a mean of milligrams and a standard deviation of milligrams. What is the probability that randomly selected light cigarettes from this company will have a total combined nicotine content...

*Sunday, October 16, 2016 by mike*

**Statistics**

If there are 6 red disks numbered 1 through 6, and 4 yellow disks numbered 7 through 10, find the probability of selecting a yellow disk given that the number selected is less than or equal to 4 or greater than or equal to 8.

*Sunday, October 16, 2016 by SHEYLAMIEL*

**Statistics**

A study of 29 female Sumatran elephants provided a 95% confidence interval for the mean shoulder height as (197.2, 235.1) cm. Consider a new study to estimate the mean shoulder height of male Sumatran elephants. Assuming the standard deviations of shoulder heights are similar ...

*Saturday, October 15, 2016 by Tabetha*

**Statistics**

A science teacher gives a test with 15 questions. This teacher is a hard grader. The teacher assigns points in the following manner: a correct answer = +1 point, an incorrect answer = -1 point, no answer = 0 points. So scores on the test could range from +15 to -15. The ...

*Friday, October 14, 2016 by sam*

**Statistics**

Suppose that 40 students take a quiz and everyone in the class scores an 80. The standard deviation of scores for this quiz is: 80 2 0

*Friday, October 14, 2016 by sam*

**Statistics**

A college statistics class conducted a survey of how students spend their money. They asked 25 students to estimate how much money they typically spend each week on fast food. They determined that the mean amount spent on fast food is $31.52 with a standard deviation of $21.60...

*Friday, October 14, 2016 by sam*

**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

*Friday, October 14, 2016 by Jay*

**Statistics**

The probability a company will hire a new employee is 0.38. Suppose three companies are randomly selected. (a) Find the probability all three companies will hire a new employee. (b) Find the probability at least one company will hire a new employee. (c) Find the probability ...

*Wednesday, October 12, 2016 by Steve*

**statistics**

consider shuffling a standard 52 deck of cards and drawing one which is black. what is the probability that the card is a 4,5,or 6

*Tuesday, October 11, 2016 by NJABU*

**statistics**

According to a survey, 21% of motorists in a large city are uninsured. Suppose that currently 21% of all motorists in this city are uninsured. Two motorists are selected at random from this city. Let x denote the number of motorists in this sample of two who are uninsured. ...

*Monday, October 10, 2016 by Anonymous*

**Statistics**

P=8.12E-4<=.01 Why is 8.12 less than .01

*Monday, October 10, 2016 by Help*

**Statistics/Probability**

An observer has measured the starting position of a toy vehicle as xs = 9.3 Â± 0.2 m and the finishing position as xf = 14.4 Â± 0.3 m. Calculate the displacement and the error in the displacement. I am not sure where to start at all.

*Monday, October 10, 2016 by Erica*

**Statistics**

Four cards are chosen at random. What is the probability that at least 2 are J's? How is this problem computed? Using Combinations or permutations?

*Sunday, October 9, 2016 by Pete*

**Statistics**

If $3000 is invested at 3% compounded monthly how much in 9 years

*Sunday, October 9, 2016 by Anonymous*

**Statistics**

If $3000 is invested at 3% compounded monthly how much in 9 years

*Sunday, October 9, 2016 by Anonymous*

**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.

*Sunday, October 9, 2016 by Allie*

**Statistics**

The weight of luggage that a randomly selected airline passenger brings onto a flight has a mean of 35 lbs and a standard deviation of 6 lbs. If a flight has 80 passengers, within what range would the average weight of their luggage fall with 95% certainty?

*Sunday, October 9, 2016 by Allie*

**Statistics**

Suppose systolic blood pressure (the higher of the two blood pressure readings) of a large group of individuals is normally distributed. If the mean is 122 and the standard deviation is 20, then

*Sunday, October 9, 2016 by JOHN*

**Statistics**

a ball rolls off a table and falls 0.80 m to the floor, landing with a speed of 4.5 m/s. 1. What was the initial speed of the ball? 2. What initial speed must the ball have if it is to land with a speed of 5.8 m/s? 3. What is the magnitude of the acceleration of the ball just ...

*Sunday, October 9, 2016 by Charlie*

**Math**

This is your question number 2 for today, out of 5 allowed. Here's your question for category 'Probability-and-statistics'. 16 teams decided to participate in a football competition. In the preliminary round, the 16 teams will br divided into 4 groups and they have...

*Sunday, October 9, 2016 by Aina*

**Statistics and**

In a survey of 144 pet owners, 31 said they own a dog, and 91 said they own a cat. 14 said they own both a dog and a cat. How many owned neither a cat nor a dog?

*Saturday, October 8, 2016 by Josh*

**STATISTICS**

A certain disease has an incidence rate of 0.6%. If the false negative rate is 4% and the false positive rate is 4%, compute the probability that a person who tests positive actually has the disease

*Friday, October 7, 2016 by Anonymous*

**Statistics**

Can anyone help me with this? Which of the following statements is true about a 99% confidence interval? a. The interval contains 99% of the population. b. The probability that the population mean is in the interval is 99%. c. The interval is wider than a 95% confidence ...

*Friday, October 7, 2016 by Angel*

**statistics**

A STAT 200 instructor is interested in whether there is any variation in the final exam grades between her two classes Data collected from the two classes are as follows: Her null hypothesis and alternative hypothesis are: (a) Determine the test statistic. Show all work; ...

*Friday, October 7, 2016 by chris*

**Statistics**

A doctor want to estimate the HDL cholesterol of all 20- to 29- year old females. how many subjects are needed to estimate the HDL cholesterol within 3 points with 99% confindence assuming s=10.5. Suppose the doctor would be content with 90% confidence. How does the decrease ...

*Friday, October 7, 2016 by Makaila*

**Statistics**

Find the minimum sample size n needed to estimate u for the given values of c, s, & E. c=0.98, s=6.5, & E=1.?

*Friday, October 7, 2016 by Makaila*

**Statistics**

It is not surprising that babies with low birth weights are at risk for developmental difficulties, but extraoridinarily large babies also face a higher than noraml risk of medical problems. In the United States the average full term single birth baby has a weight of 3.4 kg ...

*Friday, October 7, 2016 by Kelsi*

**Statistics**

Let's say that your average monthly charge is normally distributed with a mean of $500 and a standard deviation of $100. The credit card company will call anytime your purchases for the month exceed the 99th percentile. What is the dollar amount beyond which you will get a...

*Thursday, October 6, 2016 by Stacy*

**Statistics**

If a basketball player has a shooting percentage of 60% , find the probability that the player will make at least 2 of her next 9 shots?

*Wednesday, October 5, 2016 by Hannah Jorgensen*

**Statistics**

If a basketball player has a shooting percentage of 60% , find the probability that the player will make at least 4 of her next 6 shots?

*Wednesday, October 5, 2016 by Hannah Jorgensen*

**damon-steve- help statistics**

Statistics City XYZ has 8800 registered voters. There are two candidates: Peter and Paul. A poll of 600 randomly selected registered voters was conducted. We know that 331 said they'd vote for Peter and 251 said they'd vote for Paul. We also know that 18 were undecided...

*Tuesday, October 4, 2016 by sam*

**Statistics**

Consider the following frequency distribution of daily sales for a shop that was kept for the months of November and December in 2013. Daily Sales ($) 60-70 70-80 80-90 90-100 100-110 110-120 Number of days 5 11 22 13 7 3 a. From this frequency distribution, (i) draw a ...

*Saturday, October 1, 2016 by Nathan*

**Statistics**

Bill,mary,and Joe belong to a club of nineteen people. A committee of twelve is to be selected at random from the membership. How many different arrangements are possible? How many of these committees will contain Bill,Mary, and Joe at the same time?

*Thursday, September 29, 2016 by Charles*

**Statistics**

Bill, Mary, and Joe belong to a club of nineteen people. A committee of twelve is to be selected at random from the membership. How many different arrangements are possible. How many of these committees will contain Bill, Mary and Joe at the same time?

*Thursday, September 29, 2016 by Charles*

**Statistics**

Two committees, one with six and one with seven people, are to be selected from a group of eighteen people, with no one person serving on both committees at the same time. In how many ways can this be done?

*Thursday, September 29, 2016 by Charles*

**Statistics**

True or False? If a correlation is negative, then as it becomes even more negative, r2 increases.

*Thursday, September 29, 2016 by Christopher*

**statistics**

An architect estimates that the average height of the buildings of 30 or more stories in Suva is at least 500 feet. A random sample of 12 buildings is selected, and the heights in feet are shown. At = 0.025, is there enough evidence to reject the claim? 634 385 411 ...

*Thursday, September 29, 2016 by talei*

**Statistics**

23 children born. What is the probability that 22 are boys & 1 is a girl?

*Wednesday, September 28, 2016 by Kevin*

**Math**

Your statistics instructor administers a test having five multiple-choice items with four options each. List the ways in which one can guess correctly on exactly four items on this test. Are there 24 ways, because: 4! (4)(3)(2)(1) =24?

*Wednesday, September 28, 2016 by Debbie*

**Statistics**

Obtain the area under the standard normal curve to the right of z=1.32 Round your answer to four decimal places. A = the tolerance is +/-5%

*Wednesday, September 28, 2016 by Maryan*

**Language Arts**

How does the writer support the statement that dental floss promotes good dental health? With personal opinions with opinions from experts with facts that and statistics with sales information

*Wednesday, September 28, 2016 by Anonymous*

**Statistics**

How can i show that event A and B are neither mutually exclusive nor independent. And what does it mean.

*Wednesday, September 28, 2016 by Judge*

**Statistics**

The events A and B are such that P(A\B)=0.4, P(B\A)=0.25 and P(A n B)=0.12 compute the following; 1. P(A) and p(B) 2. P(A n B') and P(A' n B) 3.P(A u B)and P[(A u B)']

*Wednesday, September 28, 2016 by Mina*

**statistics**

Two dice are rolled, find the probability that the sum is less than 6 (Leave your answer as a number between 0 and 1. Round to 4 decimal places).

*Wednesday, September 28, 2016 by Tim*

**Statistics**

Your statistics instructor administers a test having five multiple-choice items with four options each. List the ways in which one can guess correctly on exactly four items on this test. Are there 24 ways, because: 4! (4)(3)(2)(1) =24?

*Tuesday, September 27, 2016 by Debbie*

**statistics**

Consider the following data on lengths of 30 pieces of metal. 18 26 15 17 7 27 24 17 10 17 23 29 28 18 10 23 16 6 12 26 5 12 23 22 24 14 16 26 19 22 a. Define an outlier. Give an example of an outlier from the above data set. [3] b. (i) Calculate and interpret the: range, mean...

*Tuesday, September 27, 2016 by TINASHE*

**Statistics**

The amount of Jen's monthly phone bill is normally distributed with a mean of $55 and a standard deviation of $12. Calculate the z score for each scenario. What percentage of her phone bills are above 79? What percentage of her phone bills are between $31 and $79. What ...

*Sunday, September 25, 2016 by Amy Penn*

**statistics**

x is normally distributed and that sample of 20 yields a mean of 42 and a variance of 25 test the hypothesis that the population standard deviation is 8 at 5% significance level.

*Sunday, September 25, 2016 by Sasanka*

**Stats, Statistics, Math**

A Statistics professor assigned 10 quizzes over the course of the semester. He wanted to see if there was a relationship between the total mark of all 10 quizzes and the final exam mark. There were 229 students who completed all the quizzes and wrote the final exam. The ...

*Saturday, September 24, 2016 by Papi*

**Statistics**

Direct mail advertisers send solicitations ("junk mail") to thousands of potential customers in the hope that some will buy the company's product. The response rate is usually quite low. Suppose a company wants to test the response to a new flyer ...

*Thursday, September 22, 2016 by Iresse*

**Statistics**

Direct mail advertisers send solicitations ("junk mail") to thousands of potential customers in the hope that some will buy the company's product. The response rate is usually quite low. Suppose a company wants to test the response to a new flyer ...

*Thursday, September 22, 2016 by Iresse*

**Statistics**

Consider the following data set: 3, 4, 6, 7, 9, 9, 11. Identify a number you could add to the set to keep the mean equal to the median. Please help me out. I have no idea how to find this and my lesson doesn't explain how to do it either. I already know that the mean and ...

*Thursday, September 22, 2016 by Me*

**Statistics**

The weight of 100 females aged 15 to 20 years has a mean of 120 pounds and a variance of 36 pounds. How many of the students has a weight less than 110 pounds?

*Thursday, September 22, 2016 by Chyrie lhu*

**statistics**

A test consists of 5 multiple questions each of which 3 answers are given, only 1 of which is correct.for each correct answer a candidate gets 2 marks but loses 1 mark for each incorrect answer.draw up table to show all possible marks and a probability associated with each ...

*Thursday, September 22, 2016 by faith*

**statistics**

Assume the lifespan of light bulbs manufactured by Bright Inc. can be modeled with a normal distribution with a mean of 300 days and a standard deviation of 40 days. 70% of light bulbs produced by Bright Inc. survive longer than how many days?

*Wednesday, September 21, 2016 by Saralynn Niealsen*

**Statistics**

In a sample of 20 men, the mean height was 178 cm. In a sample of 30 women, the mean height was 164 cm. What was the mean height for both groups put together? The answer I got by adding the two means and dividing them by 2 is 171 but it is wrong, it must be 169.9, how can I ...

*Tuesday, September 20, 2016 by W*

**college- practical statistics**

Five coins are tossed 3200 times find the frequencies of distribution of heads & tails & tabulate the results. Calculate the mean number of success & the standard deviation.

*Monday, September 19, 2016 by sathya*

**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.

*Sunday, September 18, 2016 by Addison*

**statistics**

A population of N = 10 scores has a mean of μ = 24. If one person with a score of X = 42 is removed from the population, what will be the value for the new mean?

*Friday, September 16, 2016 by patrick*

**statistics**

In general, increasing the sample size (for example, from n = 4 to n = 50) will ____ the risk of a Type I error. (Assume alpha is held constant at .05.) Select one: a. decrease b. increase c. have no influence on

*Friday, September 16, 2016 by anna*

**stats**

The weights (in pounds) of a sample of 36 individuals were recorded and the following statistics were calculated. mean = 160 range = 60 mode = 165 variance = 324 median = 170 The coefficient of variation equals: a.0.1125% b.11.25% c.203.12% d.0.20312% Do I have to find the ...

*Thursday, September 15, 2016 by Ana*

**statistics**

The weekly study times for all students in a school are normally distributed with μ = 18 hours and σ = 6 hours. If 36 students are randomly selected, find the probability that their mean study time is greater than 20 hours. My work: 20-18/(6/√36)=2/(6/6)=2/1=2...

*Thursday, September 15, 2016 by Judy*