# Sample Size

4 Questions

QUESTION 1 of 4

Professor, i have a question on example 106 on determining the sample size. How did you get the formula for that question?

QUESTION 2 of 4

Dear Prof,

As I am finishing up studying, I had a question on 7.3. I reviewed when confidence level goes up the interval width increases and vise versa and that when sample size gets larger the confidence width gets smaller. Also, what can cause margin of error to increase and decrease. But I wanted to know on Now You Try It! For section 7.3 number 4 I am still a little confused about why increasing the confidence level requires a larger sample size?

The exact question was: What effect does choosing a higher confidence level have on the required sample size needed to estimate a mean within a given margin of error and having a given standard
deviation?
Answer: . Increasing the confidence level will increase the required sample size.

Thank you for all your help this semester,

Natalie R.

QUESTION 3 of 4

I also had a question on section 7.6 number 62.

QUESTION 4 of 4

Professor McGuckian,

I was working on questions from 7.3 Now You Try It, from STATSprofessor and I noticed that the answer for number 3 was "195 children". But when I got my answer I got 195..4..... and I rounded up to 196, because as you said in your videos, one should round up when we are talking about people or things, in this case children. Am I correct to round up to 196, or is the answer sheet correct?