Chapter 12

Chapter 12

When determining whether the statements are true, students should consider whether they are always true. If a statement is sometimes true but is not always true, students should not mark it

as being true.

Students who do not select the second statement may not realize that when data is normally distributed, the mean and the median are equal, or very close to equal. Students look at diagram of a normal distribution. Because of

the symmetry of the distribution, the mean and the median are the same.

Students who have difficulty may not know how to approach the problem. List the given numbers in order from least to greatest. Since the median of the given numbers is 12, the missing number must be greater than 11. If it were greater than 15, the median of the entire set would be 13. Since it is 12, the missing number is between 11 and 15. It must be 13 in order for the median to be 12.

Students who answer incorrectly may have difficulty understanding the concepts of parameters and statistics. Remember that statistics are specific numbers relating to specific sets of data. Parameters are much broader concepts, and usually cannot be specifically calculated.

Students who answer 46% for 7c may have found the percent of students who participate in music.Be sure to cover up the second and third rows of the table to isolate the numbers that relate to the question.

Students who have difficulty with 8c may not understand that they can see the shape of the data in the stem-and-leaf plot. Make a dot plot for the evening data and compare it to the stemplot. Find the similarities, to show that it can tell whether the data is normally distributed by examining the data in either format.

Some students may not need to calculate the median or the range of the data. These questions are asking students to compare the median and range in general, not the specific values. However, some students may still need to calculate these values to better understand the data.