This list shows the lengths in feet of the 25 longest bridges in the United States. 1010 1470 1600 2000 2800 1053 1495 1632 2150 3500 1200 1596 1750 2150 3800 1207 1600 1800 2300 4200 1380 1600 1850 2310 4260 Jamie made a frequency table of the bridge data. U. S. Bridges Length (ft) Tally Frequency (first interval) || 7 (last interval) || 2
Based on the tallies and frequencies for the first and last intervals, how many intervals of what length did Jamie use?
a. 4 intervals of 1000 feet c. 6 intervals of 500 feet b. 5 intervals of 1000 feet d. 7 intervals of 500 feet