Answer: 18
Step-by-step explanation:
- The<u> sample mean</u> is the best point estimate of the population mean .
Given : A simple random sample of 5 observations from a population containing 400 elements was taken, and the following values were obtained (12 18 19 20 21).
Then , the sample mean = 
sample mean 
Hence, A point estimate of the mean is 18.
Mia walked 7km/h so after 1 hour, she is 7 km north of the house of Julia
Samantha walked 11km/h so after 1 hour, she is 11 km west of the house of Julia.
The points where Mia and Samantha are after 1 hour , and the house of Julia form a right triangle with sides 7 and 11 km. The distance between the girls, is the hypotenuse of his triangle.
by the pythagorean theorem:
Answer: 13 km
let's take admission fee= z
8z+11z=17.50+21.25
19z=38.75
z=38.25/19
z=2.4 (aprox)
Or In case of Kiara 17.50 amount paid in 8 rides
.so 1 ride=17.50/8
=2.1875
same In case of mia
so 1 ride=21.25/11
=1.9318.
but, they are not match so there is problem in your Questions.
You can see it’s 90
You can also see it because. A triangle is 180 degrees so
45+45=90
180-90=90
So x=90
