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:
q = 42
Step-by-step explanation:

Hope this helps.
Just combine all 2y=-4
Y=-2
X=-2
Answer:
$ 67.15 tax
Step-by-step explanation:
the tax would be 7.9% of 850
turn ur percent to a decimal....and " of " means multiply
0.079 * 850 = 67.15 <==