Answer:
4/5
Step-by-step explanation:
1. Do 1/2 x 0.6 which is 0.3 or 3/10
2. Add 3/10 to 1/2 which is 4/5
How do you solve this exactly what’s it called so I can solve this I keep getting decimal
Answer: C. 461
Step-by-step explanation:
We know that the formula to find the sample size is given by :-

, where
= Population standard deviation from prior study.
E = margin of error.
z* = Critical value.
As per given , we have
E= 15
Significance level : 
Critical value (Two tailed)=
Now , Required sample size = 
[Round to next integer]
Hence, the required sample size to be taken is 461.
Correct answer = C. 461