Exam Name SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. State whether you think that the variables have strong positive correlation, weak positive correlation, strong negative correlation, weak negative correlation, or no correlation. 1) The unemployment rate and the number of homeless people. 1) 2) Hours of exercise per week and blood pressure. 2) 3) Actual temperature on a given day and the temperature that had been forecast for that day 10 days previously. 3) State whether the scatter diagram shows strong positive correlation, weak positive correlation, strong negative correlation, weak negative correlation, or no correlation. 4) 4) 5) 5) A statement is made about correlation. State whether the correlation is positive or negative and whether the correlation is most likely due to coincidence, a common underlying cause, or a direct cause. 6) As Thomas's income rose over the last 20 years so has his stress level. 6) 7) People who eat a lot of junk food are heavier, on the whole, than those who do not. 7) 1
8) People who take more vacations score higher on standardized tests. 8) Answer as requested. 9) Which of the following pairs of variables is likely to have a negative correlation? 9) A) Height and weight. B) The unemployment rate and the number of homeless people C) The price of jet fuel and the price of airline tickets. D) Interest rates and the number of real estate transactions SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Find the mean for the given sample data. Unless otherwise specified, round your answer to one more decimal place than that used for the observations. 10) Bill kept track of the number of hours he spent exercising each week. The results for four 10) months are shown below. Find the mean number of hours Bill spent exercising per week. Round your answer to the nearest tenth of an hour. 8.5 8.2 8.4 7.6 6.6 8.5 6.9 8.4 8.3 8.5 7.6 8.3 6.7 8.2 8.2 8.3 6.6 6.9 Find the median for the given sample data. 11) The distances traveled (in miles) to 7 different swim meets are given below: 11) 22, 24, 33, 48, 61, 68, 85 Find the median distance traveled. Find the mode(s) for the given sample data. 12) The weights (in ounces) of 14 different apples are shown below. 12) 5.9 5.2 4.5 4.4 6.2 5.9 5.2 4.2 4.3 4.4 5.9 4.2 4.4 5.1 State how many peaks you would expect for the distribution described. 13) Voice pitch for the people in the school auditorium consisting of 6 year olds giving a concert, their mothers, and their fathers 13) Answer the question. 14) Tell which of the following distributions would have the least variation. 14) A) 100-meter times for male college seniors B) 100-meter times for college seniors C) 100-meter times for male Olympic sprinters D) 100-meter times for adults 2
15) Tell which of the following distributions would have the most variation. 15) A) Salaries of bank clerks B) Salaries of waitresses C) Salaries of CEOs of U.S. corporations D) Salaries of high-school teachers Select the requested distribution. 16) Which of the distributions has the greatest variation? 16) A) B) C) Provide an appropriate response. 17) Which quantity describes how widely data values are spread about the center of a distribution? 17) A) Skewness B) Variation C) Number of peaks D) Mean 18) Which of the following is not possible? 18) A) A distribution is symmetric and single peaked and the mode is greater than the mean. B) A distribution is symmetric and single peaked and the mean, median, and mode are all equal. C) A distribution is symmetric and the mode is different from the mean. D) Two data sets have equal means and modes but still have very different distributions. 3
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Find the range for the given data. 19) The manager of an electrical supply store measured the diameters of the rolls of wire in the inventory. The diameters of the rolls (in m) are listed below. 19) 0.484 0.587 0.156 0.426 0.298 0.116 Construct a boxplot as requested. 20) The weekly salaries (in dollars) of 24 randomly selected employees of a company are shown below. Construct a boxplot for the data set. 20) 310 320 450 460 470 500 520 540 580 600 650 700 710 840 870 900 1000 1200 1250 1300 1400 1720 2500 3700 A) B) C) D) Use the range rule of thumb to approximate the standard deviation. 21) A distribution of data has a maximum value of 80, a median value of 60.5, and a minimum of 41. Round results to the nearest tenth. A) 7.8 B) 19.5 C) 9.8 D) 5.2 21) 4
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. State whether the distribution appears to be (roughly) normal. 22) 22) State whether you would expect the data set to be normally distributed. 23) The amount of property taxes paid by homeowners 23) Provide an appropriate response. 24) Describe any similarities or differences in the two distributions represented by the boxplots below. Assume the two boxplots have the same scale. 24) State which type of average, the mean, median, or mode, would be most appropriate in the situation described. Explain your thinking. 25) A shoe manufacturer wants to know in which size they should make the most shoes. 25) Which type of average would be the most useful? 5
The stack plot below shows the value of each of Danny's investments. The stack plot contains three regions. The uppermost unshaded region represents the value of Danny's investment in individual stocks. The center shaded region represents the value of Danny's investment in mutual funds and the bottom region in black represents the value of Danny's investment in a CD. The thickness of a region at a particular time tells you its value at that time. Use the graph to answer the question. 26) In which year was the total value of Danny's investments the least? 26) 27) In which year was the value of Danny's investment in individual stocks the highest? 27) 28) In which year was the value of Danny's investment in individual stocks the least? 28) 29) In the year 1990, approximately what percentage of Danny's total investment was in the CD? 29) A) 20% B) 25% C) 15% D) 30% SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Use the graph to answer the question. 30) The time series line chart below shows the price of a volatile stock from January 1999 to December 1999. Describe the overall trend in the price during that period. 30) 6
31) The bar graph below shows the relative frequencies of the different blood types. Write a sentence describing what is revealed by the graph. 31) 32) This double-bar graph shows the number of male (M) and female (F) athletes at a university over a four-year period. 32) Compare the trend in the number of male athletes during the four-year period and the trend in the number of female athletes during the four-year period. A) The number of male athletes increased steadily over the four-year period. The number of female athletes increased in 1987 then decreased again in 1988 and 1989. B) The number of male athletes and the number of female athletes increased steadily over the four-year period. C) The number of male athletes increased steadily over the four-year period. The number of female athletes increased to a peak in 1988 and then decreased again in 1989. D) The number of female athletes increased steadily over the four-year period. The number of male athletes increased to a peak in 1988 and then decreased again in 1989. 7