Certain tubes manufactured by a company have a mean lifetime of 800 hours and a standard deviation of 60 hours. Find the probability that a random sample of 16 tubes taken from the group will have a mean lifetime (a) between 790 and 810 hours, (b) less than 785 hours, (c) more than 820 hours, (d) between 770 and 830 hours

Step-by-step explanation:

given that certain tubes manufactured by a company have a mean lifetime of 800 hours and a standard deviation of 60 hours.

Sample size n =16

Std error of sample mean =

x bar follows N(800, 15)

the probability that a random sample of 16 tubes taken from the group will have a mean lifetime

(a) between 790 and 810 hours,

=

(b) less than 785 hours

, (c) more than 820 hours,

(d) between 770 and 830 hours

=

216

Step-by-step explanation:

Volume of prism = BH

B -> Base area

Area of base:

b = 10 mi

h = 3.6mi

Area of the triangular base =

H = 12 mi

Volume of prism = 18 * 12 = 216  cubic mi