Suppose the mean height in inches of all 9th grade students at one high school is estimated. The population standard deviation is inches. The heights of 10 randomly selected students are 75,62,69,65,66,64,67,70,74 and 63.

The population mean = sample mean = x`= 67.5

Population standard deviation = 13.369

Sample standard deviation= 4.225

Step-by-step explanation:

AS the population mean is not given we will calculate it from the sample.

The mean of the sampling distribution is equal to the population mean .

The sample mean is calculated by

x`= ∑x/n= 75,+ 62, +69,+65,+66,+64, +67,+70,+74 + 63/10

x`=675/10= 67.5

The standard deviation of the sample is equal to

u = σ/ √n   where σ is the population standard deviation and n is the number of observations.

Calculating the sample mean

s= √∑xi²/n- (∑x/n)²

s= √(45741/10)- (675/10)²

s= 4.2249

σ= u*√n= 4.229 *√10

σ=13.360

i got 142 as my answer

step-by-step explanation:

4x and 6y

im not sure though