The time it takes to install a certain hardware is random. A technician installs this hardware on 64 computers with the average installation time being 42 minutes and the standard deviation of the times being 5 minutes. What is a 90% confidence interval for the popu

Step-by-step explanation:

Th formula for calculating the confidence interval of a population is expressed as shown;

CI = xbar ± Z*S/√n where;

xbar is the mean or average sample

Z is the z-score at 90% confidence

S is the standard deviation

n is the sample size

Given parameters

xbar = 42

Z at 90% CI = 1.645

S = 5

n = 64

Substituting the values into the formula will give;

CI = 42±(1.645*5/√64)

CI = 42±(1.645*5/8)

CI = 42±(1.645*0.625)

CI = 42±1.028125

CI = (42-1.028125, 42+1.028125)

CI = (40.971875, 43.028125)

Hence the 90% confidence interval for the population is approximately (40.97, 43.03) i.e

step-by-step explanation:

i found the life tables for the year 2012. 

life table of males at age 30. probability of dying between ages x and x+1

total population:  

29–30 . . . . . . . . . . . . 0.001030

30–31 . . . . . . . . . . . . 0.001061

males:  

29–30 . . . . . . . . . . . . 0.001420

30–31 . . . . . . . . . . . . 0.001448

white population

29–30 . . . . . . . . . . . . 0.001005

30–31 . . . . . . . . . . . . 0.001037

white males

29–30 . . . . . . . . . . . . 0.001372

30–31 . . . . . . . . . . . . 0.001399

non hispanic white population

29–30 . . . . . . . . . . . . 0.001083

30–31 . . . . . . . . . . . . 0.001116

non hispanic white males

29–30 . . . . . . . . . . . . 0.001477

30–31 . . . . . . . . . . . . 0.001503

jacob, non hispanic white male. 30 years old.

probability that jacob lives to be 30 years old. 

since the given probabilities are probabilities of dying, i think we simply subtract it from 1 to get the probability of living. we will use the probability of non hispanic white male.

                                          probability of living to be 30 y.o.

29 - 30 : 1 - 0.001477 = 0.998523

30 - 31 : 1 - 0.001503 = 0.998497

94

step-by-step explanation:

average the numbers and use a variable to figure out the minimum to get a 90.

(79+94+91+92+x)/5=90

x = 94