Question

The distribution of the number of hours people spend at work per day is unimodal and symmetric with a mean of 8 hours and a standard deviation of 0.5 hours. 95% of all people work between ___ and ___ hours per day? a.7 and 9 hours (T/F)

Answer 1

Answer: 95% of all people work between 7 hours and 9 hours per day and It is true.

Step-by-step explanation:

Since we have given that

Mean = 8 hours

Standard deviation = 0.5 hours

According to Empirical Rule,

at 95% confidence, it lies within 2 standard deviations  from the mean

so, lower value is given by

$mean-2\times sd\\\\=8-2\times 0.5\\\\\=8-1\\\\=7\ hours$

upper value is given by

$mean+2\times s.d\\\\=8+2\times 0.5\\\\=8+1\\\\=9\ hours$

Hence, 95% of all people work between 7 hours and 9 hours per day.

Therefore , it is true.