Answer:
The missing data value is 147
Explanation:
The mean is 120
The standard deviation is 9
Missing data value = ?
From the question, the missing data value is 3 standard deviation away from the mean.
3 standard deviation = 3 * 9 = 27
3 standard deviation from the mean = 120 + 27 = 147
The missing data value is what we get after adding 3 standard deviation from the mean.
Away here means ahead which is sum.