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.
The diagram shows that the total number of buttons with ¾ inch length is 3.
So, if she lines all the ¾ inches buttons, then the total length will be
= ¾ inches × 3
= 9/4 inches
= 2 ¼ inches
100 minus 95 equals 5
25 equals 5%
100 divided by 5 equals 20
20 times 25 equals 500
500 minus 25 equals 475
Answer:475 students present/ 500 students total in school
Answer:
b
Step-by-step explanation:
The respiratory system basically help us breathe.