This is easy, hint, you multiply ;-;
Answer: 
Step-by-step explanation:
Sampling distribution of the sample proportion
:

The sampling distribution of the sample proportion
has mean =
and standard deviation =
.
Given : The proportion of left handed people in the population is about 0.10.
i.e. p=0.10
sample size : n= 300
Then , the sampling distribution of the sample proportion
will be :-


(approx)
Hence, the sampling distribution of the sample proportion
is 
6/9
8/12
10/15
12/18
etc
etc
etc
Name of the line of reflection is called a mirror line