Answer:
324
Step-by-step explanation:
given that in a poll, 74% of the people polled answered yes to the question "Are you in favor of the death penalty for a person convicted of murder?"
i.e. Sample proportion 
Margin of error = 4% = 0.04
Confidence level =90%
Z critical value for 90% = 1.645
Margin of error = 1.645 * std error
Hence std error = 
Std error is also equal to

Sample size should be 324.
The formula is sample size = (Z critical value)^2 (pq)/(Margin of error )^2
Answer:
x=10, y = -20
Step-by-step explanation:
y = –5x + 30
x = 10
Substitute the second equation into the first
y = –5*10 + 30
y = -50 +30
y = -20
x=10, y = -20