The width of a confidence interval is defined to be the upper bound of the confidence interval minus the lower bound of the confidence interval. For example, if a confidence interval is (−2.34,9.87), then the width of this confidence interval is 9.87−(−2.34)=12.21. Assume that we are estimating the mean of a population. Assuming that the confidence coefficient, the sample mean and sample standard deviation stay the same, if we decrease the the sample size of a confidence interval from 100 to 50, then the width of that confidence interval will also decrease. True or False?

False

Step-by-step explanation:

Steps in calculating confidence Interval are

If sample size is decrased, step 3 and step 4 will increase. As a result result obtained from step 5 will also increase. Hence, confidence interval will increase if sample size is decreased

3

step-by-step explanation:

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40