Answer:
(65 - 69), (130 - 144), (115 - 129), (70 - 84)
Explanation:
The bottom 50th percentile means could be reffered to as the lower bound of the median.
Writing out the IQ scores and its frequency
IQ score
Frequency
(65-69)(70-84)(85-99)(100-114)(115-129)(130 -144)
- - 2 - - - 15 - - - - 34 - - - 36 - - - - 10 - - - - - 3
Rearranging the frequency
2, 3, 10, 15, 34, 36
Cummulative frequency = 2, 5, 15, 30, 64, 100
50% of frequency = 50/100 × total Cummulative frequency
0.5 × 100 = 50
Therefore IQ scores below the 50 Cummulative frequency point are the IQ's with frequency 2, 3, 10 and 15
The corresponding IQ scores are;
(65 - 69), (130 - 144), (115 - 129), (70 - 84)
