math
posted by takierr on .
In a set of 400 values, the mean is 121 and the standard deviation is 14. Estimate how many values fall in between each interval?
a) 107  135
b)93  149
c) 79  163

107 = µ1σ
135 = µ+1σ
So, what % is within 1σ of µ? Your Z table says 68.27% of 400 or 273
Treat the other numbers similarly