Answer:
y = 27.1
Step-by-step explanation:
We have the value of x: 
x = 12 
and we need to find the value of y in the expression: 
y = x + 15.1
as we can see by the equation, the value of y depends on the value of x.
thus, we substitute x = 12 on the previous equation: 
y = 12 + 15.1
y = 27.1
the value of y is 27.1
 
        
             
        
        
        
Given Information:
Population mean = p  = 60% = 0.60
Population size = N = 7400
Sample size = n = 50
Required Information:
Sample mean = μ = ?
standard deviation = σ = ?
Answer:
Sample mean = μ = 0.60
standard deviation = σ = 0.069
Step-by-step explanation:
We know from the central limit theorem, the sampling distribution is approximately normal as long as the expected number of successes and failures are equal or greater than 10
np ≥ 10
50*0.60 ≥ 10
30 ≥ 10 (satisfied)
n(1 - p) ≥ 10
50(1 - 0.60) ≥ 10
50(0.40) ≥ 10
20 ≥ 10  (satisfied)
The mean of the sampling distribution will be same as population mean that is
Sample mean = p = μ = 0.60
The standard deviation for this sampling distribution is given by

Where p is the population mean that is proportion of female students and n is the sample size.

Therefore, the standard deviation of the sampling distribution is 0.069.
 
        
             
        
        
        
Answer:
4
Step-by-step explanation:
The staffs takes 7.2 hours to clean 27 rooms
Therefore in one hour, the number of rooms cleaned is
= 7.2/27
= 0.2666
The number of hours required to 15 rooms is
= 0.2666×15
= 4 hours