Which of the following is TRUE?
A. 
The confidence interval is narrower if the sample size is smaller. 

B. 
The confidence interval is narrower if the level of significance is smaller. 

C. 
The confidence interval is wider if the level of confidence level is larger. 

D. 
The confidence interval is wider if the sample size is larger. 
solution:
the confidence interval is wider if the margin of error is large and confidence interval is narrower if the margin or error is small.
so, if sample size is small the margin of error will increase which result in wider confidence interval.
if samplw size is large the margin or error decrease whih result in narrower confidence interval.
also,
if significance level is small , the margin of error will increase which result in wider confidence interval.
so correct answer is
C: the confidence interval is wider if the level of confidence level is large.
(because it increase the critical value which increase the margin of error)
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