The following data are the number of minutes it took each of a group of 34 10-year-olds to do a series of abstract puzzles:

Make
(a) A frequency table.
(b) A grouped frequency table using intervals of 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-89. Based on the grouped frequency table.
(c) Make a histogram.
(d) Describe the general shape of the distribution.