The table below gives the per-pupil expenditures (in thousands of dollars) and their frequencies for the 50 states and the District of Columbia. Expenditure ($ thousands) Frequency 1-3 4-6 7-9 28 10-12 14 13-15 3 (a ) Display these data with a frequency histogram. 30 30 28 25 25 Frequency 15 14 Frequency 15- 10 1-3 46 7-9 10-12 13-15 1-3 4-6 7-9 10-12 13-15 O Expenditure ($ thousands) C Expend ture ($ thousands) 30 30 28 25 20 Frequency 15 Frequency 15 0 1-3 4-6 7-9 10-12 13-15 1-3 4-6 7-9 10-12 13-15 Expenditure ($ thousands) O Expenditure ($ thousands) (b) Find the mean per-pupil expenditure. (Round your answer to two decimal places.) thousand dollars