Answer:
1/3
Step-by-step explanation:
The number of people over 40 is 20 + 30 + 35 = 85.
So the probability is 85/255, which reduces to 1/3.
Answer:
12g
Step-by-step explanation:
Answer: 0.701
Step-by-step explanation:
Formula :
, where
significance level ,
Population standard deviation, n= sample size.
As per given, n= 22

Critical z- value for 90% confidence level : 
Then,

Hence , error bound (EBM) of the confidence interval with a 90% confidence level= ± 0.701
My guess this is answer I hope it is right
Answer:
4x+30, 1.875
Step-by-step explanation:
x+(x+30)+2x = 4x+30
4x+30=37.5
4x=7.5
x=1.875