Cramming One Thursday, researchers gave students enrolled in a section of basic Spanish a set of 50 new vocabulary words to memorize. On Friday, the students took a vocabulary test. When they returned...

Cramming One Thursday, researchers gave students enrolled in a section of basic Spanish a set of 50 new vocabulary words to memorize. On Friday, the students took a vocabulary test. When they returned to class the following Monday, they were retested—without advance warning. Both sets of test scores for the 28 students are shown below.

a) Create a graphical display to compare the two distributions of scores.

b) Write a few sentences about the scores reported on Friday and Monday.

c) Create a graphical display showing the distribution of the changes in student scores.

 d) Describe the distribution of changes.