Answer:

Step-by-step explanation:
Give data:






for 95% confidence interval

from standard z- table
confidence interval for P_1 and P_2 is



confidence interval is


Answer:
Don't believe me but I think is at A
Step-by-step explanation:
D, because a histogram does not show individual data points
Answer:
7.39682
Step-by-step explanation:
Even though 7.39682 is its approximate answer, we need to simply it.
The simple form should be 7.4 :D