Ch.15 Stats Final Exam 2024.

Ch.15 Stats Final Exam 2024. Which of the following is not measured and described by a correlation? - CORRECT ANSWER The mean difference of a relationship The relationship between age and height in trees is most likely a _____________ correlation. - CORRECT ANSWER positive Which of the following values represents a perfect correlation? - CORRECT ANSWER -1,1 The population of a bacteria colony is measured at 3:00, 3:15, and 3:30. The corresponding population values are 40, 80, and 160. Explain why this does or does not have a linear correlation. - CORRECT ANSWER This does not have a linear form because the population does not increase by the same amount every fifteen minutes. A set of n = 25 pairs of X and Y values has a Pearson correlation of r = 0.24. If each of the X values were multiplied by -3, and each Y value is increased by 2, then what is the correlation for the resulting data? - CORRECT ANSWER -24 Which of the following is an application of correlations? - CORRECT ANSWER a. Prediction b. Validity c. Reliability Which of the following are accurate considerations of correlations? - CORRECT ANSWER I. The value of a correlation can be affected greatly by the range of scores represented in the data. II. One or two extreme data points can have a dramatic effect on the value of a correlation. Suppose the correlation between age and number of hours of sleep per night for adults is -0.70. What proportion (or percent) of the variability in nightly hours of sleep can be explained by the relationship with age? - CORRECT ANSWER 49% In a correlation study, X = the age of the participant, Y = the average driving speed on the highway, and Z = the average number of accidents per year. What does represent? - CORRECT ANSWER The correlation between age and average speed with yearly accidents held constant