Answer: a) Required minimum sample size= 219
b) Required minimum sample size= 271
Step-by-step explanation:
As per given , we have
Margin of error : E= 5% =0.05
Critical z-value for 90% confidence interval : 
a) Prior estimate of true proportion: p=28%=0.28
Formula to find the sample size :-

Required minimum sample size= 219
b) If no estimate of true proportion is given , then we assume p= 0.5
Formula to find the sample size :-

Required minimum sample size= 271
Answer:
I'm confused by the layout of the first two, but I can help you with the last one!
The last one is C!
Step-by-step explanation:
Answer:
-6d^2 + 12d - 3
Step-by-step explanation:
use PEMDAS
parentheses
exponents
multiplication
division
addition
subtraction
use that order to solve problems like that.
The number of rows = 80
number of seats in 1 row = 50
total number of seats is the product of the number of rows and number of seats per row = 80*50 = 4000