Answer:
Step-by-step explanation:
If repeated sample sizes of large sizes are taken at random, and proportion P is calculated for samples the sample mean will have a normal distribution irrespective of the original distribution.
In other words, the sample proportion will follow a normal distribution with mean = p-hat and std deviation =
This is a direct corrollary of central limit theorem for sample means.
Hence we have irrespective of sample size, sample proportion will have expected value same as p-hat.
So whether sample size is 500 or 100 the p hat will have the same distribution.
Given that the ship was traveling for 4 mph faster heading west than south then let the speed of the ship heading south be x mph, the speed of the ship heading west will be (x+4) mph
the distance is given by:
distance=speed*time
distance heading south was:
x*4=4x miles
distance heading west was:
5(x+4)=5x+20
thus the total distance will be given by:
4x+(5x+20)=191
9x+20=191
9x=191-20
9x=171
x=171/9
x=19 mph
the speed the ship used to travel west was:
x+4
=19+4
=21 mph