Answer:
80 members
Step-by-step explanation:
Let the band members be= b and the chorale members= c
Then, according to question, b=c+30 and
⇒
⇒
⇒
⇒
Now, substituting the value of b=c+30, we get
⇒
⇒
⇒
⇒
Therefore,
Therefore, there are 80 members in the band.
Answer: A. (636.9, 653.1)
Step-by-step explanation:
Given : Sample size : n=56
Significance level :
Critical value :
Sample mean :
Standard deviation :
The 95% confidence interval for population mean is given by :-
Hence, 95% confidence interval for population mean is (636.9, 653.1).