Answer:
A. 24 ≤ a < 26.
B. 22.5
Step-by-step explanation:
A. Determination of the modal class interval.
Mode is the class with the highest frequency.
From the table given above, the highest frequency is 8, therefore the class will the highest frequency is:
24 ≤ a < 26.
B. To obtain the mean, we must determine the class mark. This is illustrated below:
Class >>>>> class mark >>> frequency
18 – 19 >>>> 18.5 >>>>>>>>> 3
20 – 21 >>> 20.5 >>>>>>>> 2
22 – 23 >>> 22.5 >>>>>>>> 7
24 – 25 >>> 24.5 >>>>>>>> 8
26 >>>>>>>> 26 >>>>>>>>> 0
The mean is given by the summation of the product of the class mark and frequency divided by the total frequency. This is illustrated below:
Mean = [(18.5x3) + (20.5x2) + (22.5x7) + (24.5x8) + (26x0)] / (3+2+7+8+0)
Mean = (55.5 + 41 + 157.5 + 196 + 0)/20
Mean = 450/20
Mean = 22.5
Therefore, the mean age is 22.5
