16. confidence intervals, again several factors are involved in the creation of a confidence interval. among them are the sample size, the level of confidence, and the margin of error. which statements are true?
a) for a given sample size, reducing the margin of error will mean lower confidence.
b) for a certain confidence level, you can get a smaller margin of error by selecting a bigger sample.
c) for a fixed margin of error, smaller samples will mean lower confidence.
d) for a given confidence level, a sample 9 times as large will make a margin of error one third as big.

Step-by-step explanation:

Confidence interval is one which has centre as mean.  The width of the interval would be 2 times margin of error.

Margin of error = Critical value * Std error/sq rt of sample

Hence if margin of error is lower for same n, then it means lower confidence level.  Option a is right

Similarly, if bigger the sample size, lower is margin of error . Hence option b is right

c) False.  Smaller samples make margin of error big and hence confidence intervals bigger.

d) If n becomes 9n, then margin of error becomes 1/3 Hence option d is right.

b if for most of the graph

d if y intercept

step-by-step explanation: