Study Guide: Comparing Populations

CP1.) I can calculate the measures of center: mean and median.

1.) 6, 3, 7, 1, 8, 4, 8, 9, 4 2.) 70, 55, 42, 31, 78, 93, 54, 75, 35, 41, 64

CP2.) I can calculate the measures of variability (range, quartiles, and inter-quartile range) 1.) 10, 8, 11, 4, 6, 4, 5, 12, 9, 6 2.) 32, 28, 40, 26, 41, 36, 38, 39, 29, 22, 20

Range: ______Range: ______Lower Quartile: ______Lower Quartile: ______Upper Quartile: ______Upper Quartile: ______Inter-Quartile Range: ______Inter-Quartile Range: ______

CP3) I can draw a box and whisker plot and correctly label all of the parts. Use your work from learning target CP2 to draw and correctly label a box and whisker plot for each of those sets of data.

1.) 10, 8, 11, 4, 6, 4, 5, 12, 9, 6 2.) 32, 28, 40, 26, 41, 36, 38, 39, 29, 22, 20

CP4: I can make comparative inferences based on measures of center. 1.) Before going on vacation, Michelle randomly samples the cost of hotel rooms at two different hotels. Find the mean cost per night for each hotel. Then, decide which hotel she should choose. Justify your answer! Mean Hotel S: ______Mean Hotel T: ______

Which should she choose? Justify your answer. ______

2.) The following shows the amount of people that went to 2 restaurants for lunch over a few days. Compare the medians and make an inference based on the median values.

Median for Restaurant 1:______

Median for Restaurant 2:______

Which is the best description of the medians? Which is the best inference? A.) The median for Restaurant is greater. A.) More people eat lunch at Restaurant 1 B.) The median for Restaurant 2 is greater. B.) The same amount eat at each place C.) The medians are about the same. C.) More people eat lunch at Restaurant 2

3.) There are 2 types of plants in a greenhouse. The followin dot plots show the heights of 20 plants (10 of Type 1 and 10 of Type 2). The plants are given the same amount of water. Study the dot plots. Then, answer the questions.

Mean for Type 1: ______Mean for Type 2: ______

Which is the corret inference based on the mean values? A.) Type 1 was planted first B.) The two types were planted at the same time C.) Type 2 was planted first. CP5: I can make comparative inferences based on measures of variability 1.) Use the range and inter-quartile range to describe the variability of this data set. For this data set, which is the better measure of variability and why? 3 -2 4 7 -7 6 5 17 -4

Range: ______Inter-Quartile Range: ______Is the variability “high”, “low”, or “no variability”? ______For this data set, which is the better measure of variability and why? A.) The range, because the IQR is too small. C.) The IQR because the value 17 a stray data B.) The IQR, because the range is too large. D.) The range because the value 17 is a stray data value.

2.) A researcher gave the same quiz to 2 groups. The dot plots show the times it took the people in each group to finish the quiz. Study the dot plots. Then, answer the questions below.

Which option below is the best description of the variability of this data?

A.) The variability of the times for Group S is greater than the variability of the times for Group R. B.) The variability of the times for Group R is greater than the variability of the times for Group s. C.) The variability of the timese for the two groups are about the same.

Which option below is the best comparative inference about the people in the two groups?

A.) There is less difference in time among the people in Group S than among the people in Group R. B.) There is less difference in time among the people in Group R than among the people in Group S. C.) There is about the same difference in time among the people in both groups.

3.) A group of 10 people were asked to rate 2 books, shown in the histogrms. Find the range of the ratings for each sample. Then, make a comparative inference about the books.

Range for Book 1: _____ Range for Book 2: _____

Which comparative inference is correct? A.) The ratings vary less for book 2 B. ) The ratings vary less for book 1 C.) The ratings vary to the same degree for both books.

4.) The following box plots show the frequence of test scores on a recent math test in two classes. Find the interquartile range for each class. Then make a comparative inference. IQR for Class 1: ____ IQR for Class 2: _____

Which comparative inference is correct? A.) Test sores for Class 2 are more consistent B.) Test scores for Class 1 are more consistent C.) The test scores for Class 1 and Class 2 are equally consistent.