Answer: 3
Step-by-step explanation:
Given : Standard deviation : 
Margin of error : 
Significance level : 
By using the standard normal table of z ,
Critical value : 
The formula we use to find the minimum sample size required :-

i.e. 
Hence, the number of lights should we select if we wish to estimate μ to within 5 seats and be 95 percent confident =3
Answer:
23.75
Step-by-step explanation:
C = πd
C = 3.14 x 9
C = 25.12
No an equilateral triangle has three 60° angles it has no right (90°) angle. A right angled triangle can be an isosceles triangle but not an equilateral one.