Question

The standard deviation for a set of data is 7.5. The mean is 235. What is the margin of error?

Answer 1

The margin of error is 0.97849

we are given

mean=235

so,

$n=235$

standard deviation =7.5

so,

$\sigma=7.5$

we know that

ME=2*standard error

and

$SE=\frac{\sigma }{\sqrt{n} }$

If confidence level is 95%, then we can multiply by 1.96

so, we can multiply by 2 to get ME

now, we can use marginal error formula

$ME=\frac{2\sigma }{\sqrt{n} }$

now, we can plug values

and we get

$ME=\frac{2\times 7.5 }{\sqrt{235} }$

$ME=0.97849$