# statistics

Popular questions-
## statistics

According to a college survey, 22% of all students work full time. Find the mean and standard deviation for the number of students who work full time in samples of size 16.

*asked by Hannah on March 16, 2015* -
## statistics

A tennis player makes a successful first serve 51% of the time. if she serves 9 times, what is the probability that she gets exactly 3 first serves in? assume that each serve is independent of the others.

*asked by Anonymous on April 15, 2015* -
## Statistics

The mean cost of domestic airfares in the United States rose to an all-time high of $385 per ticket. Airfares were based on the total ticket value, which consisted of the price charged by the airlines plus any additional taxes and fees. Assume domestic

*asked by Sam on June 11, 2014* -
## statistics

In the game of roulette, a wheel consists of 38 slots numbered 0, 00, 1, 2,..., 36. To play the game, a metal ball is spun around the wheel and is allowed to fall into one of the numbered slots. If the number of the slot the ball falls into

*asked by A on October 11, 2017* -
## Statistics

One of the questions in the Pew Internet & American Life Project asked adults if they used the Internet, at least occasionally. The results showed that 454 out of 478 adults aged 18 - 29 answered yes; 741 out of 833 adults aged 30 – 49 answered yes; 1058

*asked by Jen on June 16, 2014* -
## statistics

Customers arrive at a movie theater at the advertised movie time only to find that they have to sit through several previews and prepreview ads before the movie starts. Many complain that the time devoted to previews is too long (The Wall Street Journal,

*asked by sean on November 16, 2014* -
## 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

*asked by John on October 30, 2016* -
## statistics

In a batch of 8,000 clock radios 5% are defective. A sample of 14 clock radios is randomly selected without replacement from the 8,000 and tested. The entire batch will be rejected if at least one of those tested is defective. What is the probability that

*asked by havier on July 21, 2014* -
## statistics

the life spans of three randomly selected tires are 31,400 miles, 40,600 miles and 36,000 miles. Using the empirical rule, find the percentile that corresponds to each life span.

*asked by cynthia on September 8, 2013* -
## 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.

*asked by florence on October 14, 2013* -
## Statistics

A particular fruit's weights are normally distributed, with a mean of 764 grams and a standard deviation of 33 grams. The heaviest 15% of fruits weigh more than how many grams? Give your answer to the nearest gram.

*asked by Bailey on February 29, 2016* -
## Statistics

Accrotime is a manufacturer of quartz crystal watches. Accrotime researchers have shown that the watches have an average life of 32 months before certain electronic components deteriorate, causing the watch to become unreliable. The standard deviation of

*asked by Amy on November 16, 2016* -
## Statistics

The weights of the fish in a certain lake are normally distributed with a mean of 15lbs. and standard deviation of 6lbs. If a sample of 5 fish are taken from the lake, find the probability their means weights are between 12.6 lbs. and 18.6 lbs.

*asked by Amy on October 30, 2013* -
## statistics

The distribution of 27 salaries at a small company has mean $35,000 and standard deviation $2,000. Suppose the company hires a 28th 28th employee at a salary of $120,000. Which of the following claims about the new salary distribution is supported? The

*asked by Anonymous on September 25, 2019* -
## statistics

A survey for brand recognition is done and it is determined that 68% of consumers have heard of Dull Computer Company. If a survey of 800 randomly selected consumers is to be held would it be unusual for 554 of them to recognize Dull Computer Company?

*asked by Amy on October 30, 2013* -
## statistics

The probability that a house is burglarized in the city is 5%. If 50 houses are randomly selected, what is the probability that none will be burglarized?

*asked by Sherry on July 14, 2012* -
## Statistics

A sign on the gas pump of a certain chain of gasoline stations encourages customers to have their oil checked, claiming that one out of every four cars should have its oil topped up. What is the probability that exactly 3 of the next 10 cars entering a

*asked by Matt on February 10, 2007* -
## statistics

the probability that a house in an urban area will develop a leak is 5%. if 23 houses are randomly selected, what is the probability that none of the houses will develop a leak?

*asked by sara on April 28, 2013* -
## Statistics

The body temperatures of adults are normally distributed with a mean of 98.6 degree F and a standard deviation of 0.60 degree F. If 36 adults are randomly selected, find the probability that their mean body temperature is greater than 98.4 degree F.

*asked by Maile on February 10, 2013* -
## Statistics

The lengths of pregnancies are normally distributed with a mean of 273 days and a standard deviation of 20 days. If 64 women are randomly selected, find the probability that they have a mean pregnancy between 273 days and 275 days.

*asked by Jane on February 10, 2013* -
## statistics

72% working women use computers choose 5 at random whats the probility at least 1 does not use a computer whats the probility that all 5 use a computer

*asked by max on September 17, 2011* -
## Statistics

A bank categorizes its customers into one of three groups based on their banking habits. A random sample of 30 customers from each group was selected, and the number of times each customer visited the bank during the past year was recorded. The following

*asked by Anonymous on April 8, 2020* -
## statistics

A simple random sample of 40 items resulted in a sample mean of 25. The population standard deviation is 5. a. What is the standard error of the mean (to 2 decimals)? b. At 95% confidence, what is the margin of error (to 2 decimals)?

*asked by Vanessa on April 21, 2014* -
## statistics

Suppose a random sample of size 50 is selected from a population with σ = 10. Find the value of the standard error of the mean in each of the following cases (use the finite population correction factor if appropriate). a. The population size is infinite

*asked by Vanessa on April 15, 2014* -
## statistics

An IRS auditor randomly selects 3 tax returns from 58 returns of which 8 contain errors. What is the probability that she selects none of those containing errors?

*asked by Kerri on September 19, 2010* -
## Statistics

Suppose a basketball player is an excellent free throw shooter and makes 90% of his free throws (i.e., he has a 90% chance of making a single free throw). Assume that free throw shots are independent of one another. Suppose this player gets to shoot three

*asked by Grace on March 17, 2013* -
## statistics

A data set includes body temperatures of healthy adult humans for which x= 98.2 and s=0.64 F. Complete parts a) and b) below a) what is the best point estimate of the mean body temperature of all healthy humans? The best point estimate is F. b) Using the

*asked by anonymous on November 19, 2013* -
## Statistics

A physical therapist wants to determine the difference in the proportion of men and women who participate in regular sustained physical activity. What sample size should be obtained if he wishes the estimate to be within four percentage points with 99 %

*asked by Zechariah on July 6, 2016* -
## statistics

A researcher at a major hospital wishes to estimate the proportion of the adult population of the U.S. that has high blood pressure. How large a sample is needed in order to be 99% confident that the sample proportion will not differ from the tgrue

*asked by chalulu on March 13, 2011* -
## Statistics

If the probability of a newborn child being female is 0.5, find the probability that in 100 births, 55 or more will be female. Use the normal distribution to approximate the binomial distribution.

*asked by Kayla on February 10, 2013* -
## Statistics

If weight in the general population is normally distributed with an average of 160 and a standard deviation of 20 pounds, what is the probability of selecting someone who weights 120 or less or 170 or more pounds?

*asked by StudentD on August 28, 2012* -
## Statistics

A particular fruit's weights are normally distributed, with a mean of 308 grams and a standard deviation of 31 grams. The heaviest 9% of fruits weigh more than how many grams? Give your answer to the nearest gram.

*asked by Sarah S-Help! on April 12, 2011* -
## Statistics

a manufacturing machine has a 8% defect rate. if 5 items are chosen at random, what is the probability that at least one will have a defect

*asked by Mae on June 11, 2017* -
## statistics

The Economic Policy Institute periodically issues reports on wages of entry level workers. The Institute reported that entry level wages for male college graduates were $21.68 per hour and for female college graduates were $18.80 per hour in 2011 (Economic

*asked by gabby on October 1, 2015* -
## Statistics

1) A null Hypothesis assumes that a process is producing no more than a maximum allowable rate of defective items. The Type II error is to conclude that the process? 2) If 95% confidence limits for the mean Mu turn out to be (6.5,8.5)

*asked by Frank on June 13, 2005* -
## statistics

The amount of corn chips dispensed into a 16-ounce bag by the dispensing machine has been identified at possessing a normal distribution with a mean of 16.5 ounces and a standard deviation of 0.1 ounce. Suppose 400 bags of chips were randomly selected from

*asked by UG on November 8, 2011* -
## Statistics

A manufacturer ship toasters in cartons of 10. In each carton, they estimate a 20% chance that one of the toasters will need to be sent back for minor repairs. What is the probability, that in one carton there will be 5 toasters that need repair? I have no

*asked by Nick on October 5, 2013* -
## Statistics

The level of nitrogen oxides (NOX) in the exhaust of a particular car model varies with mean 0.9 grams per mile and standard deviation 0.15 grams per mile . (a) What sample size is needed so that the standard deviation of the sampling distribution is 0.01

*asked by Terra on January 12, 2012* -
## statistics

The following dotplot shows the number of strokes taken by 20 professional golfers competing at an 18-hole golf course. B? or E? I'm not sure if it would be considered categorical or continuous? It is definitely quantitive. The figure presents a dotplot

*asked by Anonymous on September 17, 2019* -
## Statistics

Standard Normanl Drill: A. Find the number z such that the proportion of observations that are less than z in a standard Normal distribution is 0.8. B. Find the number z such that 35% of all observations from a standard Normal distribution are greater than

*asked by Devon on September 10, 2007* -
## statistics

for a standard normal curve, find the z-score that separates the bottom 30% from the top 70%

*asked by kay on November 5, 2008* -
## statistics

Assume that women's heights are normally distributed with a mean given by u=64.6 in and a standard deviation given by 0=2.8in. a) If 1 woman is randomly selected, find the probability that her height is less than 65in. b) If 49 women are randomly selected,

*asked by angela on November 7, 2013* -
## Statistics

The Jones family was one of the first to come to the U.S. They had 9 children. Assuming that the probability of a child being a girl is .5, find the probability that the Jones family had at least 5 girls.

*asked by Kevin on October 1, 2017* -
## Statistics

Automobile repair costs continue to rise with the average cost now at $367 per repair (U.S. News & World Report website, January 5, 2015). Assume that the cost for an automobile repair is normally distributed with a standard deviation of $88. Answer the

*asked by Anonymous on October 29, 2018* -
## Statistics

According to insurance records a car with a certain protection system will be recovered 89% of the time. Find the probability that 3 of 7 stolen cars will be recovered.

*asked by sc on May 3, 2012* -
## 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

*asked by erin on June 23, 2013* -
## statistics

a student takes a true false test that has 13 questions and guesses randomly at each answer. Let X be the number of questions answered correctly. Find P(fewer than 4)

*asked by debbie on June 22, 2016* -
## statistics

A survey found that 25% of pet owners had their pets bathed professionally rather than do it themselves. If 18 pet owners are randomly selected, find the probability that exactly 5 people have their pets bathed professionally.

*asked by Anonymous on October 5, 2010* -
## statistics

A researcher reports an F-ratio with df = 2, 36 from an independent-measures research study. Based on the df values, how many treatments were compared in the study and what was the total number of subjects participating in the study? a. 2 treatments and 37

*asked by Robbie on November 14, 2012* -
## Statistics

Thank you!! A survey of an urban university (population of 25,450) showed that 750 of 1100 students sampled attended a home football game during the season. What inferences can be made about student attendance at football games? Using the 99% level of

*asked by Jenny on December 19, 2007* -
## statistics

You are ordering a new home theater system that consists of a TV, surround sound system, and DVD player. You can choose from 1616 different TVs, 2222 types of surround sound systems, and 1919 types of DVD players. How many different home theater systems

*asked by Hallie on July 25, 2017* -
## Statistics

Each phone call by Ali consumes an amount of time that follows an exponential distribution with mean 5 minutes. The number of different phone calls Ali makes on any given day has a Poisson distribution with mean 3. Assume that a single call always falls

*asked by Alpha on May 15, 2020* -
## Statistics

Wendy's restaurant has been recognized for having the fastest average service time among fast food restaurants. In a benchmark study, Wendy's average service time of 2.2 minutes was less than those of Burger King, Chick-fil-A, Krystal, McDonald's, Taco

*asked by Kelly Luth on February 20, 2017* -
## statistics

A sociologist is studying the social media habits of high school students in a school district. The sociologist wants to estimate the average total number of minutes spent on social media per day in the population. A random sample of 50 high school

*asked by Anonymous on March 23, 2020* -
## Statistics

The amount of rainfall in January in a certain city is normally distributed with a mean of 4.2 inches and a standard deviation of 0.5 inches. Find the value of the quartile Q1

*asked by Sennie on April 21, 2013* -
## Statistics

In a genetics experiment on peas, one sample of offspring contained 421 green peas and 166 yellow peas. Based on these results, estimate the probability of getting an offspring pea that is green. Is the result reasonably close to the value of 3/4 that was

*asked by Jana on June 13, 2013* -
## statistics

The red face cards and the black cards numbered 2-9 are put into a bag. Four cards are drawn at random without replacement. Find the following probabilities: a) All 4 cards are red b) 2 cards are red and two cards are black c) At least one of the red cards

*asked by oscar on December 12, 2010* -
## statistics

To study the effectiveness of a certain adult reading program, researchers will select a random sample of adults who are eligible for the program. The selected adults will be given a pretest before beginning the program and a posttest after completing the

*asked by Anonymous on March 23, 2020* -
## Statistics

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a standard deviation of 3 hours, what is the required sample size if the error should be

*asked by Robin on September 5, 2010* -
## Statistics

Suppose that 30% of all college students smoke cigarettes. A sample of 18 is selected randomly. What is the probability that exactly 10 students smoke? Round your answer to four decimal places.

*asked by Anonymous on November 6, 2016* -
## statistics

A police department reports that the probabilities that 0, 1, 2, and 3 burglaries will be reported in a given day are 0.50, 0.41, 0.05, and 0.04, respectively. Find the standard deviation for the probability distribution. Round answer to the nearest

*asked by darius on August 28, 2007* -
## statistics

The number of hours per week that the television is turned on is determined for each family in a sample. The mean of the data is 30 hours and the median is 26.2 hours. Twenty-four of the families in the sample turned on the television for 15 hours or less

*asked by Anonymous on October 3, 2015* -
## statistics

high temperatures in a certain city for the of the month of august follow a uniform distribution over the interval 73 degreef to 103 degree f find the high temperature which 90% of the august days exceeded

*asked by Anonymous on November 7, 2011* -
## Statistics

If the alpha level is changed from a=.05 to a=.01. a. What happens to the boundaries for the critical region? b. What happens to the probability of a Type I error?

*asked by Lyn on December 20, 2013* -
## statistics

The director of an alumni association for a university wants to look at the relationship between the number of years since graduation and the amount of monetary contribution an alumnus makes to the university. He collects data on 50 alumni who have made

*asked by David on September 22, 2012* -
## Statistics

Thickness measurements of ancient prehistoric Native American pot shards discovered in a Hopi village are approximately normally distributed, with a mean of 4.9millimeters (mm) and a standard deviation of 1.5 mm. For a randomly found shard, find the

*asked by Tamia on April 21, 2019* -
## Statistics

An automatic machine in a manufacturing process is operating properly if the lengths of an important subcomponent are independently and normally distributed with a mean of 120 cm and a standard deviation of 4.7 cm. Find the probability that if 3 are

*asked by Meghan on September 21, 2011* -
## Statistics

A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful if the average time spent on the deliveries does not exceed 30 minutes. The

*asked by Katie on November 8, 2013* -
## Statistics

The closing price of Schnur Sporting Goods, Inc., common stock is uniformly distributed between $17 and 35 per share. What is the probability that the stock price will be: More than $31? Less than or equal to $23?

*asked by Barbara on November 21, 2010* -
## 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

*asked by kasey on March 4, 2009* -
## statistics

Over the past several months, an adult patient has been treated for tetany (severe muscle spasms). This condition is associated with an average total calcium level below 6 mg/dl. Recently, the patient's total calcium tests gave the following readings (in

*asked by Interval Estimate on April 11, 2015* -
## Statistics

Coaching companies claim that their courses can raise the SAT scores of high school students. But students !@#$%^&take the SAT without paying for coaching also usually raise their scores. A random sample of students who took the SAT twice found 427 who

*asked by Anonymous on May 22, 2014* -
## statistics

the life of light bulbs is distributed normally. The variance of the life time is 225 and the mean lifetime of a bulb is 590 hours. Find the probability of a bulb lasting for at most 603 hours. Yeah, WTF??? Why me!??!

*asked by Logan on May 3, 2012* -
## statistics

The average life of Canadian women is 73.75 years and the standard deviation of the women's life expectancy in Canada is 6.5 years. Using the Chebyshev's theorem, determine the minimum percentage of women in Canada whose life expectancy is between 64 and

*asked by mzb on January 22, 2013* -
## Statistics

The home states of a certain group of people are distributed as follows: 53 percent are from MISSOURI, 21 percent are from KANSAS, and 26 percent are from IOWA. (No one in the group had a home state other than one of these three.) (Note: Your answer to the

*asked by Lucy King on March 20, 2012* -
## statistics

The Information Systems Audit and Control Association surveyed office workers to learn about the anticipated usage of office computers for personal holiday shopping. Assume that the number of hours a worker spends doing holiday shopping on an office

*asked by Jenna on April 4, 2017* -
## Statistics

A certain organization recommends the use of passwords with the following format: consonant comma consonant, consonant comma vowel comma consonant comma vowel comma consonant comma number comma number consonant, vowel, consonant, vowel, consonant,

*asked by Naomi on June 21, 2018* -
## Statistics

A particular fruit's weights are normally distributed, with a mean of 353 grams and a standard deviation of 6 grams. If you pick one fruit at random, what is the probability that it will weigh between 334 grams and 344 grams?

*asked by Daniel on May 4, 2015* -
## Statistics

Suppose that grade point averages of undergraduate students at one university have a bell-shaped distribution with a mean of 2.62 and a standard deviation of 0.43. Using the empirical rule, what percentage of the students have grade point averages that are

*asked by Jose on September 18, 2017* -
## statistics

{Exercise 3.55} Morningstar tracks the total return for a large number of mutual funds. The following table shows the total return and the number of funds for four categories of mutual funds (Morningstar Funds500, 2008). a. Using the number of funds as

*asked by abdull on October 16, 2011* -
## Statistics

if a seed is planted, it has a 70% chance of growing into a healthy plant.if 6 seeds are planted, what is the probability that exactly 1 doesn't grow?

*asked by Mae on June 11, 2017* -
## statistics

Fast Auto Service provides oil and lube service for cars. It is known that the mean time taken for oil and lube service at this garage is 15 minutes per car and the standard deviation is 2.4 minutes. The management wants to promote the business by

*asked by Karinna on February 14, 2009* -
## Statistics

IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15. Find the x- score that corresponds to a z-score of 2.33.

*asked by chalulu on March 13, 2011* -
## statistics

Ina study designed to test the effectiveness magnets for treating back pain, 35 patients were given a treatment with magnets and also a sham treatment without magnets. Pain was measured using a scale from 0(no pain) to 100(extreme pain) after the given

*asked by anonymous on November 18, 2013* -
## statistics

a pizza shop owner wishes to find the 95% confidence interval of the true mean cost of a large plain pizza. how large should the sample be if she wishes to be accurate to within $0.15? a previous study showed that the standard deviation of the price was

*asked by paula on March 17, 2013* -
## Statistics

Data are collected on the 35 students in a history course. Which of the following is not a variable of the data set ? A-student birth month B-political affiliation of student C-student age D-student address E-number of students in the data set

*asked by Stephanie on September 22, 2019* -
## Statistics

A major department store chain is interested in estimating the average amount its credit card customers spent on their first visit to the chain's new store in the mall. Fifteen credit card accounts were randomly sampled and analyzed with the following

*asked by Melanie on November 14, 2012* -
## statistics

Suppose that diastolic blood pressure readings of adult males have a bell-shaped distribution with a mean of 84 84 mmHg and a standard deviation of 9 9 mmHg. Using the empirical rule, what percentage of adult males have diastolic blood pressure readings

*asked by Anonymous on May 3, 2017* -
## Statistics

A national caterer determined that 87% of the people who sampled their food said that it was delicious. A random sample of 144 people is obtained from a population of 5000. The 144 people are asked to sample the caterer's food. If sample proportion, P^, is

*asked by Grace on March 22, 2013* -
## statistics

Richard has been given a 5-question multiple-choice quiz in his history class. Each question has three answers, of which only one is correct. Since Richard has not attended the class recently, he doesn't know any of the answers. The success occurs if

*asked by Anonymous on November 9, 2010* -
## statistics

A researcher wishes to estimate the proportion of college students who cheat on exams. A poll of 490 college students showed that 33% of them had, or intended to, cheat on examinations. Find the margin of error for the 95% confidence interval. solution I

*asked by Lucky Lady on June 19, 2014* -
## statistics

A researcher used an analysis of variance to compare three treatment conditions with a separate sample of n = 8 participants in each treatment. The results of the analysis are shown in the following summary. Fill in all missing values in the table. (Hint:

*asked by Robbie on November 15, 2012* -
## statistics

A regression analysis between sales (in $1000) and advertising (in $100) resulted in the following least squares line: = 75 + 6x. This implies that if advertising is $800, then the predicted amount of sales (in dollars) is: A) $4875 B) $123,000 C) $487,500

*asked by Danny on August 18, 2009* -
## statistics

Jim Tree sells trees. The mean length of the trees purchased was 68 inches with a standard deviation of 10 inches. Jim wants to know what percent of his sales were more than 84 inches tall. He can use the standard normal distribution to help him. He asks,

*asked by Jessie on March 20, 2013* -
## Statistics

Find the probability of getting a prime number thrice by tossing a die 10 times.

*asked by Barney on May 7, 2017* -
## statistics

A new extended-life light bulb has an average service life of 750 hours, with a standard deviation of 50 hours. If the service life of these light bulbs approximates a normal distribution, about what percent of the distribution will be between 600 hours

*asked by MARIA on January 9, 2012* -
## Statistics

A survey of 250 lobster fisherman found that they catch an average of 32 pounds of lobster per day with a standard deviation of four pounds. If a random sample of 30 lobster fisherman is selected, what is the probability that their average catch is less

*asked by Mark on May 7, 2014* -
## statistics

In a carnival game, a player spins a wheel that stops with the pointer on one (and only one) of three colors. The likelihood of the pointer landing on each color is as follows: 65 percent BLUE, 22 percent RED, and 13 percent GREEN. Note: Your answers

*asked by Sydney on March 31, 2013* -
## statistics

The weight of a small Starbucks coffee is a normally distributed random variable with a mean of 410 grams and a standard deviation of 10 grams. Find the weight that corresponds to each eventa. A.Highest 30 percent b. Middle 70 percent to c. Highest 90

*asked by MD on April 7, 2013* -
## STATISTICS

According to Masterfoods, the company that manufactures M&M’s, 12% of peanut M&M’s are brown, 15% are yellow, 12% are red, 23% are blue, 23% are orange and 15% are green. Compute the probability that two randomly selected peanut M&M’s are both blue.

*asked by MIA on July 24, 2013*