Popular questions
  1. 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
  2. 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
  3. 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
  4. 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
  5. stats

    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
  6. 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

    asked by Ana on September 15, 2016
  7. 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
  8. 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
  9. 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
  10. 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
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. stats

    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
  17. 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
  18. 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
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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
  26. 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
  27. 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
  28. 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
  29. 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
  30. 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
  31. 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
  32. 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
  33. 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
  34. 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
  35. Stats

    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
  36. 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
  37. 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
  38. 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
  39. 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
  40. 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
  41. 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
  42. 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
  43. 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
  44. 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
  45. 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
  46. 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
  47. 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
  48. 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
  49. 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
  50. 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
  51. 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
  52. 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
  53. 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
  54. 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
  55. 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
  56. 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
  57. 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
  58. 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
  59. 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
  60. 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
  61. 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
  62. Stats

    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
  63. stats

    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
  64. 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
  65. 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
  66. 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
  67. 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
  68. 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
  69. 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
  70. 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
  71. stats

    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
  72. 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
  73. 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
  74. 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
  75. 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
  76. 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
  77. 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
  78. 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
  79. 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
  80. 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
  81. 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
  82. 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
  83. 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
  84. 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
  85. 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
  86. 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
  87. 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
  88. 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
  89. 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
  90. 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
  91. 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
  92. 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
  93. 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
  94. 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
  95. 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
  96. 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
  97. 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
  98. 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
  99. 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
  100. 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


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