Find the mean of the distribution given below.
| Value (x) | 4 | 6 | 9 | 10 | 15 |
|---|---|---|---|---|---|
| Frequency (f) | 5 | 10 | 10 | 7 | 8 |
Answer: A
To find the mean of a frequency distribution, we use the formula Mean = \(\frac{\sum(f_i x_i)}{\sum f_i}\).
\(\sum(f_i x_i) = (4\times5) + (6\times10) + (9\times10) + (10\times7) + (15\times8) = 20 + 60 + 90 + 70 + 120 = 360\).
Wait, 20+60=80, 80+90=170, 170+70=240, 240+120=360. Correct. Let me re-calculate again. 20+60+90+70+120=360.
\(\sum f_i = 5+10+10+7+8 = 40\).
Mean = \(\frac{360}{40} = 9\). This is not an option. Let me recheck the question data and options. Let's assume the last frequency is 10 instead of 8. Then sum of freq is 42. Sum of fx is 20+60+90+70+150 = 390. 390/42 is not a clean number. I will correct the sum in the exp, my manual sum was wrong. Sum is 360. Mean is 9. Let me make one of the options 9.