# stats

Popular questions-
## stats

if the relation between x and u is 3x + 4u + 7 = 0 and the correlation coefficient between x and y is -0.6, then what is correlation coefficient u and y a)-0.6 b)0.8 c)0.6 d)-0.8

*asked by nnn on October 20, 2015* -
## Stats

About 10% of the population of a large country is math phobic. If two people are randomly selected what is the probability both are math phobic? And hat is the probability that at least one is math phobic? Any way to do this on stat crunch?

*asked by Michelle on October 11, 2015* -
## stats

If one of the 87 flights is randomly selected, find the probability that the flight selected arrived on time given that it was and Upstate Airlines flight. _____________On Time Flights _________________ Late Flights Podunk ___________ 33

*asked by J.T. on July 14, 2010* -
## stats

A common computer programming rule is that names of variables must be between one and eight characters long. The first character can be any of the 26 letters, while successive characters can be any of the 26 letters or any of the 10 digits. For

*asked by derrek on September 23, 2017* -
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Find the probability of at least 2 girls in 10 births. Assume that male and female births are equally likely and that the births are independent events.

*asked by Greg on March 16, 2015* -
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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

*asked by Ana on September 15, 2016* -
## stats

Scores on a test are approximately normally distributed with a mean of 70 and a standard deviation of 9. The teacher wants to give A’s to the top 10% of students, B’s to the next 25%, and C’s to the next 42%. a.) what is the bottom cutoff for a C

*asked by vanessa on April 25, 2016* -
## Stats

In the past, the mean running time for a certain type of flashlight battery has been 9.8 hours. The manufacturer has introduced a change in the production method and wants to perform a hypothesis test to determine whether the mean running time has

*asked by Amy on November 22, 2014* -
## Stats

A roulett wheel has 38 slots in which a ball can land two of e slots are green, 18 are red, 18 are black. The ball is equally likely to land in any slot, and each spin of the wheel is assumed to be independent. A)if the wheel is spun twice what is the

*asked by Salina on March 10, 2013* -
## stats

The incomes of trainees at a local mill are normally distributed with a mean of $1100 and a standard deviation $150. What percentage of trainees earn less than $900 a month?

*asked by J.T. on July 20, 2010* -
## Stats

A pizza parlor has 12 different toppings available for its pizzas, and 2 of these toppings are pepperoni and anchovies. If a customer picks 2 toppings at random, find the probability that neither topping is anchovies. Round your answer to four decimal

*asked by Anon on July 16, 2015* -
## STATS

The top selling Red and Voss tire is rated 70,000 miles means nothing. In fact, the distance the tires can run until they wear out is a normally distributed random variable with a mean of 82,000 miles and a standard deviation of 6,400. a. What is the

*asked by SANDRA on September 16, 2011* -
## stats

Based on data from a statistical abstract, only about 10% of senior citizens (65 years old or older) get the flu each year. However, about 27% of the people under 65 years old get the flu each year. In the general population, there are 15% senior citizens

*asked by jay on February 28, 2017* -
## Stats

The time that it takes a randomly selected job applicant to perform a certain task has a distribution that can be approximated by a normal distribution with a mean value of 150 sec and a standard deviation of 20 sec. The fastest 10% are to be given

*asked by B on October 2, 2013* -
## stats

Find the z-scores for which 92 % of the distribution's area lies between minus z and z.

*asked by chris on September 18, 2016* -
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A random sample of mid-sized cars tested for fuel consumption gave a mean of miles per gallon with a standard deviation of miles per gallon. Assuming that the miles per gallon given by all mid-sized cars have a normal distribution, find a confidence

*asked by Anonymous on April 9, 2014* -
## stats

According to a survey of American households, the probability that the residents own 2 cars if annual household income is over $50,000 is 80%. Of the households surveyed, 60% had incomes over $50,000 and 70% had 2 cars. The probability that annual

*asked by cali on January 20, 2016* -
## stats

This week we practice with Binomial Distribution. You can use Appendix Table E or Excel Function Binomdist. About 30% of adults in United States have college degree. (probability that person has college degree is p = 0.30). If N adults are randomly

*asked by mary on November 10, 2011* -
## stats

The mean tax-return preparation fee H&R Block charged retail customers last year was $183 (The Wall Street Journal, March 7, 2012). Use this price as the population mean and assume the population standard deviation of preparation fees is $50. Round your

*asked by megan on June 26, 2015* -
## Stats

In a study of children with a particular disorder, parents were asked to rate their child on a variety of items related to how well their child performs different tasks. One item was "Has difficulty organizing work," rated on a five-point scale of 0 to 4

*asked by James on July 9, 2012* -
## Stats

Health insurers are beginning to offer telemedicine services online that replace the common office visit. Wellpoint provides a video service that allows subscribers to connect with a physician online and receive prescribed treatments (Bloomberg

*asked by Kay on April 6, 2019* -
## Stats

Running times for 400 meters are Normally distributed for young men between 18 and 30 years of age with a mean of 93 seconds and a standard deviation of 16 seconds. Thus, 99.7% of running times are approximately between Need help

*asked by Lisa on February 12, 2017* -
## stats

Jason, a freshman at a local college, just completed 15 credit hours. His grade report is presented below. Course: Calculus, Biology, English, Music, P.E. Credit Hours 5, 4, 3, 2, 1 Grades C, A, D, B, A The local university uses a 4 point grading system,

*asked by Ana on September 15, 2016* -
## stats

A company with a large fleet of cars hopes to keep gasoline costs down and sets a goal of attaining a fleet average of at least 26 miles per gallon. To see if the goal is being met they check the gasoline usage for 50 company trips chosen at random,

*asked by GLEN on July 13, 2011* -
## Stats

Exercise 6-8 The Downtown Parking Authority of Tampa, Florida, reported the following information for a sample of 235 customers on the number of hours cars are parked and the amount they are charged. Number of Hours Frequency Amount Charged 1 18 $3 2 33 7

*asked by Nicole on September 28, 2010* -
## stats

Suppose x has a normal distribution with sigma = 1.2. Find the minimal sample size required so that for a 95% confidence interval, the maximal margin of error E = 0.5.

*asked by Anonymous on March 6, 2016* -
## stats

if 60 % of all women are employed outside the home find the probability that in a sample of 20 women at least 10 are employed

*asked by Anonymous on November 12, 2014* -
## STATS

Solve the problem. Round the point estimate to the nearest thousandth. 22 randomly picked people were asked if they rented or owned their own home, 9 said they rented. Obtain a point estimate of the proportion of home owners. A) 0.290 B) 0.591 C) 0.636 D)

*asked by Anonymous on September 25, 2011* -
## stats

TABLE 1 The general manager of a chain of pharmaceutical stores reported the results of a regression analysis, designed to predict the annual sales for all the stores in the chain (Y) – measured in millions of dollars. One independent variable used to

*asked by Maggie on July 4, 2011* -
## Stats

Childhood participation in sports, cultural groups, and youth groups appears to be related to improved self-esteem for adolescents. (McGee, Williams, Howden-Chapman, Martin & Kawachi, 2006). In representative study, a sample of n = 100 adolescents with a

*asked by Adriana on November 16, 2016* -
## Stats

You draw two marbles at random from a jar that has 20 red marbles and 30 black marbles without replacement. What is the probability that both marbles are red?

*asked by Anastasia on November 15, 2016* -
## Stats

The probability that a person has blue eyes is 16%. Three unrelated people are selected at random. a. Find the probability that all three have blue eyes: b. Find the probability that none of the three have blue eyes c. Find the probability that one of the

*asked by Dave on April 30, 2013* -
## Stats

The area between the mean and a Z score of +1.50 is 43.32%. This score is higher than ___ of the score in the distribution.

*asked by DeeDee on February 1, 2013* -
## Stats

Most decks of playing cards contain 4 suits - hearts, clubs, diamonds, and spades. If you choose one card from the deck at random, what is the probability that it will be from the suit hearts?

*asked by Char on September 29, 2014* -
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In 1898 L. J. Bortkiewicz published a book entitled The Law of Small Numbers. He used data collected over 20 years to show that the number of soldiers killed by horse kicks each year in each corps in the Prussian cavalry followed a Poisson distribution

*asked by Ashley on February 25, 2014* -
## Stats

Recently, an automobile insurance company performed a study of a random sample of 15 of its customers to determine if there is a positive relationship between the number of miles driven and the age of the driver. The sample correlation coefficient is

*asked by Breezy on June 13, 2011* -
## stats

The probability is 0.35 that a traffic fatality involves an intoxicated or alcohol-impaired driver or nonoccupant. In ten traffic fatalities, find the probability that the number, Y, which involve an intoxicated or alcohol-impaired driver or nonoccupant is

*asked by k on March 16, 2020* -
## Stats

The host of a dinner party purchases wine based on the weighted average of clarity (10%), bouquet (5%), friendliness to the palate (5%), storage ability of opened bottles (40%), and price (40%). Suppose that Bone Ranch Wave has scores in these categories

*asked by Monica on May 5, 2016* -
## Stats

Which of the following are binomial experiments? (more than one is possible) 1.) A store finds that 32% of people who enter the store will make a purchase. During a day, 50 people enter the store. The random variable represents the number of people who

*asked by Semmy on October 13, 2015* -
## Stats

In a sample of 400 voters, 360 indicated they favor the incumbent governor. The 95% confidence interval? I can't figure out what to do without a standard deviation!!!!!!!!

*asked by Anonymous on December 7, 2014* -
## Stats

Suppose the scores of students on an exam are Normally distributed with a mean of 297 and a standard deviation of 66. Then approximately 99.7% of the exam scores lie between the numbers _____and _______such that the mean is halfway between these two

*asked by Please and Thank you!!! on October 27, 2014* -
## Stats

The high temperature X (in degrees Fahrenheit) on January days in Columbus, Ohio varies according to the Normal distribution with mean 21 and standard deviation 10. The value of P(X < 10) is

*asked by Tracy on March 29, 2014* -
## Stats

A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO is less than 1 in every one thousand. State the null hypothesis and the alternative hypothesis for a test of significance.

*asked by Cecil on May 22, 2013* -
## Stats

A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, the absorption amounts of a sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6,

*asked by Tom on April 29, 2012* -
## Stats

At a major International Airport, 0.49 of the flights arrive on time. A sample of 12 flights is studied. What is the probability that more than 3 of them arrived on time? Write only a number as your answer. Round to 2 decimal places (for example 0.24). Do

*asked by Semmy on October 13, 2015* -
## Stats

Richard has just been given a 4-question multiple-choice quiz in his history class. Each question has five answers, of which only one is correct. Since Richard has not attended class recently, he doesn't know any of the answers. Assuming that Richard

*asked by Collie on October 3, 2012* -
## Stats

The wildlife department has been feeding a special food to rainbow trout fingerlings in a pond. A sample of the weights of 40 trout revealed that the mean weight is 402.7 grams and the standatd deviation 8alE8 gr. What is the probability that the mean

*asked by Brad on June 10, 2011* -
## Stats

The Centers for Disease Control reported the percentage of people 18 years of age and older who smoke (CDC website, December 14, 2014). Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the

*asked by Colby on December 4, 2019* -
## stats

Which of the following variables for data about a track team is a discrete variable? C would be the discrete variable?? The height of a team member A The weight of a team member B The number of times that a team member finished first in a race C The time

*asked by Anonymous on September 15, 2019* -
## Stats

A sociology professor assigns letter grades on a test according to the following scheme. A: Top 14% of scores B: scores below the top 14% and above the bottom 55% C: scores below the top 45% and above the bottom 17% D: scores below the top 83% and above

*asked by Benjamin on October 14, 2017* -
## Stats

Suppose you pay $1.00 to roll a fair die with the understanding that you will get back $3.00 for rolling a 6 or a 3, nothing otherwise. What is your expected value?

*asked by Jonell on March 16, 2016* -
## STATS

Winning the jackpot in a particular lottery requires that you select the correct two numbers between 1 and 56 and, in a separate drawing, you must also select the correct single number between 1 and 59. Find the probability of winning the jackpot.

*asked by BMETA on June 12, 2015* -
## Stats

The Internal Revenue Service (IRS) provides a toll-free help line for taxpayers to call in and get answers to questions as they prepare their tax returns. In recent years, the IRS has been inundated with taxpayer calls and has redesigned its phone service

*asked by Avery on December 7, 2014* -
## stats

A normal population has mean 100 and variance 25. How large must the random sample be if we want the standard error of the sample average to be 1.5? I know the answer is 12. Would someone please be able to explain! and share what formula they used

*asked by sam on December 3, 2014* -
## stats

Question 5 of 10 Why are partial regression coefficients necessary in multiple regression? (Points : 1) Multiple variables each provide some of the same information. Each variable involved contributes a unique error component. Each variable involved is

*asked by please help on July 20, 2014* -
## Stats

You want to rent an unfurnished one-bedroom apartment in Boston next year. The mean monthly rent for a random sample of 14 apartments advertised in the local newspaper is $1200. Assume that the standard deviation is $230. Find a 95% confidence interval for

*asked by James on July 9, 2012* -
## stats

A random sample of 12 joggers was asked to keep track and report the number of miles they ran last week the responses are: 5.5 7.2 1.6 22.0 8.7 2.8 5.3 3.4 12.5 18.6 8.3 6.6 a) Compare the three statistics that measure central location. b) Briefly describe

*asked by qui on January 31, 2011* -
## STATS

Using the z-score of ±1.645 for the 5 percent cutoff and the z-score of ±1.96 for the 2.5 percent in the tail, identify the subject identification (ID) number for subjects who are closest to the cutoff for the upper 2.5 percent and 5 percent of the

*asked by Slomo on January 12, 2016* -
## stats

A box contains 16 white and 16 black marbles. Construct a sample space for the experiment of randomly drawing out, with replacement, three marbles in succession and noting the color each time. (To draw “with replacement” means that each marble is put

*asked by Hailey on September 22, 2015* -
## STATS

The following confidence interval is obtained for a population proportion, p:0.556 < p < 0.584. What is the point estimate, p?

*asked by 1234 on September 30, 2012* -
## Stats

A class of 85 students writing an exam had a mean mark of 74.2 write down the total sum of the 85 grades.

*asked by Rachael on September 26, 2012* -
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The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience. Admissions Probability 1,080 0.5 1,340 0.2 1,660 0.3

*asked by Nicole on September 28, 2010* -
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Researchers are investigating whether people who exercise with a training partner have a greater increase, on average, in targeted exercise intensity compared with people who exercise alone. Two methods of collecting data have been proposed. Method I:

*asked by Anonymous on April 16, 2020* -
## Stats

Suppose the number of cell phones in a household has a binomial distribution with parameters n = 17, and p = 40 %. Find the probability of a household having (Keep at least 4 digits) (a) 11 or 13 cell phones? (b) 11 or fewer cell phones ? (c) 14 or more

*asked by terry on July 6, 2017* -
## stats

The probability is 0.7 that a person shopping at a certain store will spend less than $20. For groups of size 13, find the mean number who spend less than $20.

*asked by Johnny on July 6, 2017* -
## Stats

The GRE has a combined verbal and quantitative mean of 1000 and standard deviation of 200. Scores range from 200 to 1600. a. what % of the persons score above 1300? b. above 800? c. below 1200? d. above what score do the top 20% of the test-takers score?

*asked by Terry on April 17, 2016* -
## STATS

An IRS auditor randomly selects 3 tax returns from 55 returns of which six contain errors. What is the probability that she selects none of those containing errors?

*asked by Jodi on March 16, 2015* -
## Stats

Research shows that 14% of 6th graders in K-6 schools have tried cigarettes and 61% of 7th graders in 8-9 or 7-9 middle schools have tried cigarettes. what is the absolute increase to the nearest percent? A. 77% B. 336% C. 436% D. 47% I don't know this one

*asked by Amy on December 15, 2014* -
## stats

To estimate the mean score of those who took the Medical College Admission Test on your campus, you will obtain the scores of an SRS of students. From published information you know that the scores are approximately Normal with standard deviation about

*asked by Aman on November 6, 2013* -
## Stats

Suppose the time it takes for a purchasing agent to complete an online ordering process is normally distributed with a mean of 8 minutes and a standard deviation of 2 minutes. Suppose a random sample of 25 ordering processes is selected. The standard

*asked by Jerry on November 13, 2011* -
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If other factors are held constant, how does increasing the sample variance affect the value of the independent-measures t statistic and the likelihood of rejecting the null hypothesis?

*asked by mike on July 3, 2011* -
## stats

Among the contestants in a competition are 44 women and 26 men. if 5 winners are randomly selected, what is the probability that they are all men?

*asked by jEFFREY on July 14, 2010* -
## Stats

One of the questions in the Pew Internet & American Life Project asked adults if they used the Internet at least occasionally (Pew website, October 23, 2012). The results showed that 454 out of 478 adults aged 18 - 29 answered Yes; 741 out of 833 adults

*asked by jaycee on November 21, 2019* -
## stats

A preliminary survey shows that 35% of college students smoke. In a class of 42 students, what is the probability that more than half the students smoke?

*asked by ...... on February 20, 2017* -
## Stats

One of the questions on a survey of 1,000 adults asked if today's children will be better off than their parents (Rasmussen Reports website October 26, 2012). Representative data are shown in the file ChildOutlook. A response of Yes indicates that the

*asked by HANNAH TURNER on November 15, 2016* -
## Stats

8.0235% of the employees of the Acme Tire store are enrolled in a 401k at the store. If the company has 600 employees, what is the probability that less than 40 employees are entered in the 401k.

*asked by Sam on April 6, 2016* -
## Stats

A telephone company’s goal is to have no more than five monthly line failures on any 100 kilometres of line. The company currently experiences an average of two monthly line failures per 50 kilometres of line. Let x denote the number of monthly line

*asked by Kaylee on November 28, 2015* -
## Stats

Makers of a new pain-relieving medication claim that it relieves chronic pain faster than the current top-selling pain reliever on the market. A double-blind experiment was conducted in which 10 people who experience chronic pain were randomly selected to

*asked by Serena on May 10, 2015* -
## Stats

Let the random variable X be a random number with the uniform density curve given below. P(0.6 < X < 0.9) is

*asked by Tracy on March 29, 2014* -
## Stats

About 35% of the population has blue eyes (based on a study at Indiana University). a. If someone is randomly selected, what is the probability that he or she does not have blue eyes?

*asked by Yolanda on November 14, 2012* -
## stats

A company that manufactures and bottles apple juice has a machine that automatically fills 16-ounce bottles. There is some variation, however, in the exact amount of juice dispensed into each bottle. From a large number of observations taken over a long

*asked by a on January 29, 2011* -
## stats

An automobile repair shop has determined that the average service time on an automobile is 2 hours with a standard deviation of 32 minutes. A random sample of 64 out of 400 services is selected. What is the probability that this sample will have a mean

*asked by sandy on November 11, 2009* -
## Stats

The lifetime of a particular type of battery is normally distributed with a mean of 1100 days and a standard deviation of 80 days. The manufacturer randomly selects 400 batteries of this type and ships them to a departmental store. (a) What is the mean and

*asked by Dherain on June 5, 2008* -
## stats

Which of the following can be reasonably modeled by a normal distribution? The favorite colors of students in a kindergarten class A The heights of tomato plants that were all planted on the same day B The percent of employees from a company who attended a

*asked by Anonymous on September 30, 2019* -
## stats

Which of the following variables for data about a track team is a discrete variable? C?? The height of a team member A The weight of a team member B The number of times that a team member finished first in a race C The time recorded for the last race that

*asked by Anonymous on September 14, 2019* -
## stats

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

*asked by Anonymous on September 14, 2019* -
## stats

find area of indicated region under the standard normal curve the numbers are -.45 and 2.11 its shaded more towards the right i got the answer .3438 why is it not 1-normalcdf (-.45, 2.11, 0, 1) and why is it just normalcdf(-.45,2.11,0,1)

*asked by feather on February 22, 2019* -
## Stats

In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 72 and a standard deviation of 9. Grades are to be assigned according to the following rule: The top 10% receive A's. The next 20% receive B's.

*asked by Mark on November 18, 2016* -
## stats

Anita's a fast food chain specializing in hotdogs and garlic fries, keeps track of the proportion of its customers who decide to eat in the restaurant so it can make decisions reguarding possible construction of the in-store play areas.the attendance of

*asked by Riley on October 1, 2016* -
## Stats

Describe how to use a source of random data to simulate multiple trials of this situation. A student guesses on all 10 questions of a multiple-choice quiz. Each question has three choices. a. Assign 00-09 to all of the correct answers and 10-29 for all the

*asked by Bailey on July 28, 2016* -
## 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?

*asked by genia on July 26, 2015* -
## stats

Three firms carry inventories that differ in size. Firm A's inventory contains 2000 items, firm B's inventory contains 5000 items, and firm C's inventory contains 10,000 items. The population standard deviation for the cost of the items in each firm's

*asked by megan on June 26, 2015* -
## stats

A research firm conducted a survey to determine the mean amount people spend at a popular coffee shop during a week. They found the amounts spent per week followed a normal distribution, with a population standard deviation of $4. A sample of 49 customers

*asked by Anonymous on November 4, 2014* -
## 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?

*asked by bob on October 21, 2014* -
## Stats

The annual precipitation for one city is normally distributed with a mean of 28 inches and a standard deviation of 3.4 inches. Fill in the blanks. In 95% of the years, the precipitation in this city is between __________ and __________ inches. Apply the

*asked by Amy on September 26, 2014* -
## Stats

1.Number of people in attendance at a baseball game qualitative/ordinal qualitative/nominal quantitative/discrete quantitative/continuous 2. number of tracks on a CD qualitative/ordinal qualitative/nominal quantitative/discrete quantitative/continuous

*asked by Kathryn on August 11, 2014* -
## Stats

the typical saturday the oil change facility will perform 40 oil changes between 10 am and 12pm. treating this as a random sample, what mean oil change time would there be a 10% chance of being at or below? There is a 10% chance of being at or below a mean

*asked by Sandra on April 21, 2014* -
## Stats

Of 43 bank customers depositing a check, 18 received some cash back. (a) Construct a 90 percent confidence interval for the proportion of all depositors who ask for cash back. (b) Check the normality assumption.

*asked by Kevin on April 18, 2014* -
## Stats

4. A least squares regression line to predict a student’s Stat145 test score (from 0-to-100) from the number of hours studied was determined from a class of 55 Stat145 students: ̂ = 48.2 + 2.21x. One student in the class studied for 18 hours and scored

*asked by Tracy on March 7, 2014* -
## Stats

two tailed test for experiment with N= 24. Can't find table of t critical values, but tcv@ df=13. Compared tobt with tcv. Will this more likely create type I or type II error?

*asked by Michele on June 6, 2013*