Section 3.1 HW Practice Exam Questions And Answers Guaranteed Pass.

A histogram of a set of data indicates that the distribution of the data is skewed right. Which measure of central tendency will likely be larger, the mean or the median? Why? - correct answer The mean will likely be larger because the extreme values in the right tail tend to pull the mean in the direction of the tail. True or False: A data set will always have exactly one mode. - correct answer False Find the population mean or sample mean as indicated. Sample: 22, 18, 33, 12, 20 - correct answer a. x^- =15 For a large sporting event the broadcasters sold 66 ad slots for a total revenue of $142 million. What was the mean price per ad slot? The mean price per ad slot was - correct answer $2.2 million The median for the given set of six ordered data values is 29.5 7, 12, 25, ___, 41, 51 What is the missing value? - correct answer 34 A concrete mix is designed to withstand 3000 pounds per square inch (psi) of pressure. The following data represent the strength of nine randomly selected casts (in psi). 3950, 4090, 3300, 3100, 2930, 3820, 4090, 4050, 3700 Compute the mean, median and mode strength of the concrete (in psi). a. Compute the mean strength of the concrete. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. b. Compute the median strength of the concrete. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. c. Compute the mode strength of the concrete. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. - correct answer a. 3670 psi of pressure b. 3820 psi of pressure c. 4090 psi of pressure For the histogram on the right determine whether the mean is greater than, less than, or approximately equal to the median. Justify your answer. - correct answer x^- = M because the histogram is symmetric The acidity or alkalinity of a solution is measured using pH. A pH less than 7 is acidic; a pH greater than 7 is alkaline. The accompanying data represent the pH in samples of bottled water and tap water. a) Determine the mean, median, and mode pH for each type of water a2. Let xT represent the sample mean pH of the tap water. Let xB represent the sample mean pH of the bottled water. Determine the value of xT−xB, the sample mean difference in pH of the two types of water. a3. What can be said about the differences between the two types of water? b) Suppose the pH of 7.34 in tap water was incorrectly recorded as 3.74. How does this affect the mean? the median? What property of the median does this illustrate? b2. If the pH of 7.34 in tap water was incorrectly recorded as 3.74 the median pH would be b3. What property of the median does this illustrate? - correct answer a. tap: 7.535; 7.495; 7.49 bottled: 5.22; 5.225; 5.28 a2. 2.315 a3. Bottled water is more acidic than tap water. b. 7.235 b2. 7.495 b3. It illustrates the resistance of the median. The accompanying data represent the weights (in grams) of a simple random sample of 10 M&M plain candies. Determine the shape of the distribution of weights of M&Ms by drawing a frequency histogram. Find the mean and median. Which measure of central tendency better describes the weight of a plain M&M? Mean & Median The ________ better describes the weight because the distribution is _________. - correct answer graph D; .87; .87 mean; symmetric