Answer: 0.4667
Step-by-step explanation:
According to 68–95–99.7 rule , About 99.7% of all data values lies with in 3 standard deviations from population mean (
).
Here , margin of error = 3s , where s is standard deviation.
As per given , we have want our sample mean
to estimate μ μ with an error of no more than 1.4 point in either direction.
If 99.7% of all samples give an
within 1.4 , it means that

Divide boths ides by 3 , we get

Hence, So
must have 0.4667 as standard deviation so that 99.7 % 99.7% of all samples give an
within 1.4 point of μ .
You need to know these two formulas:

For example,

Answer:
D. 14.32
Step-by-step explanation:
The formula for standard deviation is:

The mean μ is 33.
The (x minus μ) squared are 361, 49, 49, 361 respectively.
So that the SD = 
Answer:
1 +√21 + 1 - √21
2 2
Step-by-step explanation: