A scientist calculated the mean and standard deviation of a data set to be Mu = 120 and Sigma = 9. She then found that she was missing one data value from the set. She knows that the missing data value was exactly 3 standard deviations away from the mean. What was the missing data value?

The missing data value is 147

Step-by-step 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.

312312

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional