If all possible samples of size n are drawn from an infinite population with a mean of 20 and a standard deviation of 5, then the standard error of the sampling distribution of sample means is equal to 1.0 only for samples of size:

25

Step-by-step explanation:

We know that the standard error of the sampling distribution of sample means is

Standard error=standard deviation/√n

√n=standard deviation/Standard error

n=(standard deviation/Standard error)²

We are given that standard deviation=5 and standard error=1. So,

n=(5/1)²

n=5²

n=25.

Thus, the required sample size is 25.

2 over 5

step-by-step explanation:

the 2: 3 ratio is the length of the ac segment to the cb segment total length. this implies that the ratio between segment ac length and segment ab length is 2: 5. point c is 2/5 from a to b, so the required fraction is 2/5.

the answer is  

a.

4,624π mm2

step-by-step explanation: