This topic contains a solution. Click here to go to the answer

Author Question: A light bulb manufacturer claims its light bulbs will last 500 hours on average. The lifetime of a ... (Read 1133 times)

haleyc112

  • Hero Member
  • *****
  • Posts: 600
A light bulb manufacturer claims its light bulbs will last 500 hours on average. The lifetime of a light bulb is assumed to follow an exponential distribution.
 a. What is the probability that the light bulb will have to be replaced within 500 hours?
  b. What is the probability that the light bulb will last more than 1,000 hours?
  c. What is the probability that the light bulb will last between 200 and 800 hours?

Question 2

A university planner wants to determine the proportion of spring semester students who will attend summer school. She surveys 32 current students and discovers that 12 will return for summer school.
 a. Construct a 90 confidence interval estimate for the proportion of current spring students who will return for summer school.
 b. With a .95 probability, what sample size would have to be selected to provide a margin of error of 3 or less?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

mariahkathleeen

  • Sr. Member
  • ****
  • Posts: 337
Answer to Question 1

a. .632
b. .135
c. .468

Answer to Question 2

a. .234 to .516
b. 1001





 

Did you know?

Recent studies have shown that the number of medication errors increases in relation to the number of orders that are verified per pharmacist, per work shift.

Did you know?

More than 150,000 Americans killed by cardiovascular disease are younger than the age of 65 years.

Did you know?

Adolescents often feel clumsy during puberty because during this time of development, their hands and feet grow faster than their arms and legs do. The body is therefore out of proportion. One out of five adolescents actually experiences growing pains during this period.

Did you know?

The use of salicylates dates back 2,500 years to Hippocrates's recommendation of willow bark (from which a salicylate is derived) as an aid to the pains of childbirth. However, overdosage of salicylates can harm body fluids, electrolytes, the CNS, the GI tract, the ears, the lungs, the blood, the liver, and the kidneys and cause coma or death.

Did you know?

Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.

For a complete list of videos, visit our video library