You are a researcher studying the lifespan of a certain species of bacteria. A preliminary sample of 30 bacteria reveals a sample mean of x=74 hours with a standard deviation of s=5.4 hours. You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.65 hours at a 99% level of confidence.
What sample size should you gather to achieve a 0.65 hour margin of error? Round your answer up to the nearest whole number.

458

Step-by-step explanation:

Margin of error = critical value × standard error

At 99% confidence, the critical value is z = 2.576.

The standard error is σ/√n = 5.4/√n.

Given the desired margin of error is 0.65:

0.65 = 2.576 × 5.4/√n

n = 458

4+n=5

step-by-step explanation:

this is because the four is four hours and the n represents the 1 extra hour over the weekend.

b= i'm srry i don't know that one.

4+n=5 n=1 because if vernon plays 5 hours a week then 4+1=5 hours.

hope this : )

180 square centimeters

step-by-step explanation: