WGU C955 Probability and Statistics Pre Assessment Exam Questions and Answers (Verified by Expert) Newest Update 2026/2027.

WGU C955 Probability and Statistics Pre Assessment Exam Questions and Answers (Verified by Expert) Newest Update 2026/2027. 1. In a class of 25 students, the following test scores were obtained: 31, 46, 49, 52, 55, 67, 68, 68, 69, 69, 71, 73, 73, 75, 75, 78, 79, 82, 84, 84, 85, 87, 91, 92, 97 Which statement is true about this distribution ANS The distribution is skewed to the left. 2. In a class of 25 students, the following test scores were obtained: 51, 59, 59, 59, 67, 68, 68, 69, 69, 71, 73, 73, 75, 75, 78, 79, 82, 84, 85, 85, 87, 91, 92, 93, 93 A histogram of interval width 10 starting with the interval [50, 60] was constructed using the above data. 2 / 8 Which statement is true about this distribution as depicted by the histogram ANS It is a unimodal symmetric distribution. 3. The following 5-number summaries were obtained for two distributions, A and B: A 3.2 4.9 5.7 5.9 8.2 B 2.7 5.1 5.7 6.9 7.5 The distribution of A is skewed to the right, whereas the distribution of B is skewed to the left. How are the means of the two distributions related ANS The mean of A is higher than the mean of B. 7. A local ice cream shop kept track of the number of cans of cold carbonated beverages it sold each day (Y) and the temperature that day (X) for 2 months during the summer. The data are displayed in the following scatterplot: 3 / 8 Which statement describes the relationship between X and Y as it appears in the scatterplot ANS If the outlier were removed, r would increase. 8. The following table shows the age of a child in months (x) and the hours of sleep the child needs during nap time each day (y). Age Nap Time 1 8 3 5 6 3.25 9 3 12 2.5 18 2.25 24 2 36 1.5 4 / 8 The equation of the least squares regression line is y = -0.1351 x + 5.2787 y equals negative 0.1351 x plus 5.2787. Which two statements about the situation are true ANS There is a strong curvilin- ear relationship between the two variables. and The regression line predicts that an 11-month-old child would need 3.79 hour long naps. 3. In a class of 25 students, the following scores were received on a quiz: 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 9, 9, 9, 9 For this distribution, what is the most appropriate measure of central tendency ANS Either the mean or the median 5. A study is conducted to determine if there is a difference in final exam scores in high school classrooms when different types of instruction are used. The two types of instruction included in the study are direct instruction and computer-based instruction. What are the explanatory (X) and response (Y) variables for this study ANS The type of instruction is the explanatory variable (X) and the test score is the response variable (Y). 6. A store asked 350 of its customers whether they were satisfied with their service. The responses were also classified according to the gender of the customers.