Questions and Answers > Grand Canyon University MAT-274 - GCU - Probability and Statistics . EXAm 1.

Document Content and Description Below

2. Does the frequency distribution appear to have a normal distribution? Explain. then decrease to a low frequency, and the distribution is approximately symmetric. 3. When playing roulette at a c... asino 4. A sample of blood pressure measurements is taken for a group of adults 5, For a data set of chest sizes 6. In a study of retractions in biomedical journals 7. Use the data in the following table, which lists drive-thru order accuracy at popular fast food chains. Assume that orders are randomly selected from those included in the table. The events are not independent because choosing the first order affects the choice of the second order. 8. A drug is designed to treat insomnia. In a clinical trial of the drug, amounts of sleep each night are measured before and after subjects have been treated with the drug. 9. Determine whether the given value is from a discrete or continuous data set. When a car is randomly selected, it is found to have a length of 15.03 ft a length of 15.03 ft. 11. A study was conducted to determine how people get jobs. The table below lists data from 400 randomly selected subjects. 12. The table below shows the frequency distribution of the rainfall on 52 consecutive Saturdays in a certain city. Use the frequency distribution to construct a histogram. Do the data appear to have a distribution that is approximately normal? 13. An engineer is going to redesign an ejection seat for an airplane. 14. Which word is associated with multiplication when computing probabilities? 16. A certain group of test subjects had pulse rates with a mean of 75.9 beats per minute and a standard deviation of 11.9 beats per minute. 17. Why is it important to learn about bad graphs? 18. Among 350 randomly selected drivers in the 20-24 age bracket, 15 were in a car crash in the last year. 19. When testing a new treatment, what is the difference between statistical significance and practical significance? Can a treatment have statistical significance, but not practical significance? 21. P (A or B) indicates _____ 26. The table lists weights (pounds) and highway mileage amounts (mpg) for seven automobiles 27. A survey showed that 74% of adults need correction. Less then 0.05? 29. In a survey of 1213 people, 926 people said they voted in a recent presidential election. 30. A continuity correction is made to a discrete whole number x in the binomial distribution by representing the discrete whole number x by which of the following intervals? 31. Which of the following is a biased estimator? That is, which of the following does not target the population parameter? 33. Which of the following is NOT a voluntary response sample? 35. Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 664 subjects, each was asked how often he or she drank milk. The survey subjects were internet users who responded to a question that was posted on a news website. 37. The normal quantile plot shown to the right represents duration times (in seconds) of eruptions of a certain geyser from the accompanying date 38. Determine whether the given procedure results in a binomial distribution (or a distribution that can be treated as binomial). If the procedure is not binomial, identify at least one requirement that is not satisfied. Four different senators from the current U.S. Congress are randomly selected without replacement and whether or not they've served over 2 terms is recorded 39. Heights of statistics students were obtained by a teacher as part of an experiment conducted for the class. 40. Identify which type of sampling is used: random, systematic, convenience, stratified, or cluster. To determine customer opinion of their food quality, General Foods randomly selects 90 city blocks during a certain week and surveys all homes within the city blocks. 41. What is a scatterplot and how does it help us? 42. Which of the following is always true? 43. Which of the following would be classified as categorical data? 44. In a probability histogram, there is a correspondence between 45. For a data set of weights (pounds) and highway fuel consumption amounts (mpg) of four types of automobile, the linear correlation coefficient is found and the P-value is 0.042. Write a statement that interprets the P-value and includes a conclusion about linear correlation. 46. If np≥5 and nq≥5, estimate P(more than 5) with n=13 and p=0.3 by using the normal distribution as an approximation to the binomial distribution; if np<5 or nq<5, then state that the normal approximation is not suitable. 47. A student wants to simulate 24 birthdays, but she does not have a calculator or software program available, so she makes up 24 numbers between 1 and 365. Is it okay to conduct the simulation this way? Why or why not? 49. Suppose that the sitting back-to-knee length for a group of adults has a normal distribution. 49. The accompanying data represent women's median earnings as a percentage of men's median earnings for recent years beginning with 1989. Is there a trend? How does it appear to affect women? Construct a time-series graph. 50. A _______ probability of an event is a probability obtained with knowledge that some other event has already occurred. 51. The random variable x represents the number of phone calls an author receives in a day, and it has a Poisson distribution with a mean of 6.4 calls. What are the possible values of x? Is a value of x=3.8possible? Is x a discrete random variable or a continuous random variable? 52. The symbol for sample standard deviation is s The symbol for population standard deviation is a The symbol for sample variance is s^2 The symbol for population variance is a^2 53. A sociologist randomly selects single adults for different groups of three, and the random variable x is the number in the group who say that the most fun way to flirt is in person. 54. Use the given data values (a sample of female arm circumferences in centimeters) 55. Refer to the definition of simple random sample available below and its accompanying definition of random sample enclosed within parentheses. Determine whether each of the following is a simple random sample and a random sample. 56. If calculations are time-consuming and if a sample size is no more than 5% of the size of the population, the _______ states to treat the selections as being independent (even if the selections are technically dependent). 58. A normal distribution is informally described as a probability distribution that is "bell-shaped" when graphed. Draw a rough sketch of a curve having the bell shape that is characteristic of a normal distribution. 59. Identify the type of observational study. A researcher plans to obtain data by interviewing spouses of victims who perished in hurricane to see how they're coping now. 60. Listed below are foot lengths in inches for 11 randomly selected people taken in 1988 61. A professional basketball star who had a reputation for being a poor free throw shooter made 5331of the 9746 free throws that he attempted, for a success ratio of 0.547. 62. The _______ states that if, under a given assumption, the probability of a particular observed event is exceptionally small (such as less than 0.05), we conclude that the assumption is probably not correct. 63. A survey found that women's heights are normally distributed 64. What conditions would produce a negative z-score 65. The ages (years) of three government officials when they died in office were 54 , 45, and 59. Complete parts (a) through (d). The population range is not equal to the mean of the sample ranges (it is also not equal to the age of the oldest official or age of the youngest official at the time of death). d. The sample ranges do not target the population range, therefore, sample ranges do not make good estimators of population ranges 67. On their first date, Kelly asks Mike to guess the date of her birth, not including the year. Complete parts a through c below. 68. If we have a large voluntary response sample consisting of weights of subjects who chose to respond to a survey posted on the Internet, can a graph help to overcome the deficiency of having a voluntary response sample? 69. The body temperatures of a group of healthy adults have a bell-shaped distribution with a mean of 98.14degrees°F and a standard deviation of 0.42degrees°F. Using the empirical rule, find each approximate percentage below. 99.40degrees°F? About 68% of all values fall with 1 standard deviation of the mean. About 95% of all values fall with 2 standard deviation of the mean. About 99.7% of all values fall with 3 standard deviation of the mean. What is the approximate percentage of healthy adults with body temperatures between 97.72degrees°F and 98.56degrees°F? 68% 70. Determine whether the given value is a statistic or a parameter. A homeowner measured the voltage supplied to his home on all 30 days of a given month, and the average (mean) value is 112.3 volts.. 71. In a double-blind experiment designed to test the effectiveness of a new medication as a treatment for lower back pain, 1643 patients were randomly assigned to one of three groups: (1) the 547 subjects in the placebo group were given pills containing no medication; (2) 550 subjects were in a group given pills with the new medication taken at regular intervals; (3) 546 subjects were in a group given pills with the new medication to be taken when needed for pain relief. What does it mean to say that the experiment was "double-blind"? 72. The given data represent the number of people from a town, aged 25-64, who subscribe to a certain print magazine. Construct a frequency polygon. Does the graph suggest that the distribution is skewed? If so, how? 73. In horse racing, a trifecta is a bet that the first three finishers in a race are selected, and they are selected in the correct order. Does a trifecta involve combinations or permutations? Explain 74. Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below. Mood levels of "happy " "alright" and "sad" 75. To the right are the outcomes that are possible when a couple has three children. Assume that boy equally likely, so that the eight simple events are equally likely. Find the probability that when a three children, there are exactly 3 girls 76. The _______ for a procedure consists of all possible simple events or all outcomes that cannot be broken down any further 77. Let a population consist of the values 11 cigarettes, 21 cigarettes, and 22 cigarettes smoked in a day 78. The data represents the heights of eruptions by a geyser. Use the heights to construct a stemplot. Identify the two values that are closest to the middle when the data are sorted in order from lowest to highest. 79. A researcher collects a simple random sample of grade-point averages of statistics students, and she calculates the mean of this sample. Under what conditions can that sample mean be treated as a value from a population having a normal distribution? 80. How could you use a random-digit generator or random-number table to simulate rain if you knew that 50% of the time with conditions as you have today, it will rain? 81. The accompanying table describes the random variable x, the numbers of adults in groups of five who reported sleepwalking. Complete parts (a) through (d) below. 82. The data table to the right represents the volumes of a generic soda brand. Complete parts (a) and (b) below. 83. In a certain weather forecast comma the chance of a thunderstorm is stated as 13% Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive. 85. 86. Which characteristic of data is a measure of the amount that the data values vary? 87. In an experiment, college students were given either four quarters or a $1 bill and they could either keep the money or spend it on gum. The results are summarized in the table. Complete parts (a) through (c) below 88. Determine whether the study is an experiment or an observational study, and then identify a major problem with the study. A study involved 22,071 male physicians. Based on random selections, 11,037 of them were treated with aspirin and the other 11,034 were given placebos. The study was stopped early because it became clear that aspirin reduced the risk of myocardial infarctions by a substantial amount. 90. Annual incomes are known to have a distribution that is skewed to the right instead of being normally distributed. Assume that we collect a large (n>30) random sample of annual incomes. Can the distribution of incomes in that sample be approximated by a normal distribution because the sample is large? Why or why not? 91. Determine if the following statement represents a meaningful ratio, so the ratio level of measurement applies. [Show More]

Last updated: 1 year ago

Preview 1 out of 14 pages