91Ó°ÊÓ

Which of the following is an incorrect statement? (A) In histograms, relative areas correspond to relative frequencies. (B) In histograms, frequencies can be determined from relative heights. (C) Symmetric histograms may have multiple peaks. (D) Two students working with the same set of data may come up with histograms that look different. (E) Displaying outliers may be more problematic when using histograms than when using stemplots.

Which of the following is a true statement? (A) Stemplots are useful for both quantitative and categorical data sets. (B) Stemplots are equally useful for small and very large data sets. (C) Stemplots can show symmetry, gaps, clusters, and outliers. (D) Stemplots may or may not show individual values. (E) Stems may be skipped if there is no data value for a particular stem.

Suppose the average score on a national test is 500 with a standard deviation of 100 . If each score is increased by \(25 \%,\) what are the new mean and standard deviation, respectively? (A) 500 and 100 (B) 525 and 100 (C) 625 and 100 (D) 625 and 105 (E) 625 and 125

Refer to the following: 250 students are taking a college history course. There is one class of size 150 and four classes of size 25 . What is the average class size among the five classes? (A) 35 (B) 50 (C) 100 (D) 125 (E) 137.5

A teacher is teaching two AP Statistics classes. On the final exam, the 20 students in the first class averaged \(92,\) while the 25 students in the second class averaged only \(83 .\) If the teacher combines the classes, what will the average final exam score be? (A) 87 (B) 87.5 (C) 88 (D) None of the above. (E) More information is needed to make this calculation.

Allan famously quipped that when he moved from Pennsylvania to California, the average IQ dropped in both states. What would have had to been true for this to happen? (A) Allan's IQ was greater than the average IQ in both Pennsylvania and California. (B) Allan's IQ was greater than the average IQ in Pennsylvania and less than the average IQ in California. (C) Allan's IQ was less than the average IQ in Pennsylvania and greater than the average IQ in California. (D) Allan's IQ was less than the average IQ in both Pennsylvania and California. (E) There is no way for Allan's statement to be true.

Refer to the following: 250 students are taking a college history course. There is one class of size 150 and four classes of size 25 . Among the 250 students, what is the average size, per student, of their history class? (A) 35 (B) 50 (C) 100 (D) 125 (E) 137.5