The lifetime (in hours) of a 60-watt light bulb is a random variable that has a normal distribution with σ = 30 hours. a random sample of 25 bulbs put on test produced a sample mean lifetime of = 1038. construct a 92% confidence interval estimate for the mean lifetime μ. if it were desired to cut the confidence interval to half its length while keeping the same 92% level, what size sample would be required to achieve this?

38.5

step-by-step explanation:

lets say, first number = r

second number = 3r+7

total = 49

(r)+(3r+7)= 49

4r+7 = 49

4r = 42

r = 42/4

r= 10.5

3r+7 = 3(10.5)+7 = 38.5

hope this

example 2 – simplify: step 1: completely factor both the numerators and denominators of all fractions. step 2: change the division sign to a multiplication sign and flip (or reciprocate) the fraction after the division sign; essential you need to multiply by the reciprocal. step 3 : cancel or reduce the fractions.

step-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!

1. sometimes

2. never true

3. sometimes

step-by-step explanation:

these are pretty self explanatory if you know what supp right and com angles are