Answer: (0.00306,0.00334)
Step-by-step explanation:
Given : Sample size : n= 420000
The number of users developed cancer of the brain or nervous system =134
Then , the proportion of users developed cancer of the brain or nervous system :

Significance level : 
Critical value : 
The confidence interval for population proportion is given by :-

Hence, the 90% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system is (0.00306,0.00334).
Answer:
60pi = ⅓ × pi × r² × h
180 = r²h
Assuming r and h are whole numbers,
r = 3 m , h = 180/3² = 20 m
Diameter = 6 m
Or,
r = 6 m, h = 180/6² = 5 m
Diameter = 12 m
We are asked to solve for the area of the sector in a circle which central angle measures 125° and the circle also has a diameter of 13 feet. To solve this problem, we need to use the formula in solving area of a sector and it is shown below:
Area of a sector = (central angle / 360) * pi*r²
In the problem, we have radius = diameter / 2 which is r = 13/2 and r = 6.5 feet
Area = (125/360)*pi(6.5)²
Area = (125/360) * 3.14*6.5²
Area = 46.06 feet²
The answer is 46.1 feet².
C, it has the ratio of $9 per hour which is a greater ration than all the other options.
Hope this helps!