A student measured the lead content of a paint sample 4 times. The standard deviation of the measurements was found to be 0.76% of the average. Calculate the confidence interval at the 90% confidence level.

Step-by-step explanation:

From the question we are told that:

Sample size

Standard deviation

Confidence level

Degree of Freedom

Therefore

Test T from table is given

Generally the equation for Confidence interval CI is mathematically given by

6/20

step-by-step explanation:

the surface area is 124cm²

step-by-step explanation:

length: 4cm

width: 9cm

height:   2cm