Monica measures the number of bacteria that are living on her petri dish. Each day, she measures the amount of change in the number of bacteria. These amounts create a geometric sequence. Use the data in the table to determine the sum of the amounts of change in the bacteria after the seventh day. Day
1 3
2 −6
3 12
4 −24

Answers:
-15
15
127
129

Arandom sample of n = 25 observations is taken from a n(µ, σ ) population. a 95% confidence interval for µ was calculated to be (42.16, 57.84). the researcher feels that this interval is too wide. you want to reduce the interval to a width at most 12 units. a) for a confidence level of 95%, calculate the smallest sample size needed. b) for a sample size fixed at n = 25, calculate the largest confidence level 100(1 − α)% needed.