In order to officailly 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. previous contracts indicate that the standard deviation is 4.5 hours. how large a sample must be selected?

20

Step-by-step explanation:

Formula to find the sample size :

Given : Significance level :

Critical value :

Margin of error :

Standard deviation:

Then, we have

Hence, the minimum sample size must be 20.

never fear papaguy is here

answer

answer:  

step-by-step explanation:

odd numbers are only divisible by 1 and itself.

even numbers are divisible by more than 1 and itself.

for example 6 is even because it is divisible by more than 1 and its self. 1 x 6= 6 ; 2 x 3= 6

and 7 is odd because only 7 x 1 equals seveb