An investigator compares the durability of two different compounds used in the manufacture of a certain automobile brake lining. A sample of 243 brakes using Compound 1 yields an average brake life of 37,866 miles. A sample of 268 brakes using Compound 2 yields an average brake life of 45,789 miles. Assume that the population standard deviation for Compound 1 is 4414 miles, while the population standard deviation for Compound 2 is 2368 miles. Determine the 95% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2.

THEREFORE THE CONFIDENCE INTERVAL from the Z table = ±1.645

Step-by-step explanation:

Confidence level = 95% = 0.95

compound 1

Number of samples ( n1 ) = 243

Average brake life ( x1 ) = 37866 miles

standard deviation ( ∝ ) = 4414 miles

compound 2

number of samples ( n2 ) = 268

Average brake life ( x2 ) = 45789 miles

standard deviation ( ∝ ) = 2368 miles

Determine the 95% confidence interval for the true difference between average lifetimes

significance level (β) = 1 - confidence level = 1 - 0.95 = 0.05

standard error =    = ( 4414^2/243) + (2368^2/268) =

critical value = 0.05/2 =Z 0.025 = 1.645

THEREFORE THE CRITICAL VALE from the Z table = ±1.645

the highest percentage for deaths in construction from highest to lowest is as follows: falls, struck by objects, electrocution, and caught-in/between. these four are collectively known as fatal four.

in the case of falls, the type that is responsible for the overall highest death in the category is falls from roofs.

the answer is (-8,-5)

step-by-step explanation:

the endpoint to midpoint is half the length. the length is (-2,-1) so when you are at the midpoint just add it to it to find your answer -6+(-2)= -8 and -4+(-1)=-5 so (-8,-5)