20( -1.5r + 0.75)
Multiply everything by 20
= -30r + 15
3/4 is greater
hope it helps
Answer:
Step-by-step explanation:
Given that in order to efficiently bid on a contract, a contractor wants to be 95% confident that his error is less than two hours in estimating the average time it takes to install tile flooring.
Std deviation =4.5 errors
95% confidence interval = Mean±1.96*std dev
Hence we have

Sample size should be 20.