Answer:
Step-by-step explanation:
height(h) mid value frequency
in cm x f xf
120<t≤124 122 7 854
124<t≤128 126 8 1008
128<t≤132 130 13 1690
132<t≤136 134 9 1206
136<t≤140 138 3 414
total 40 5172
mean height=5172÷40=129.30
mean height=129.30 cm
b.
it is an estimate i have taken only mid value,for example in the interval all the 7 students may be of length greater than 122 and viceverse.
Similarly for other intervals.
