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 1129 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?

Atropine was named after the Greek goddess Atropos, the oldest and ugliest of the three sisters known as the Fates, who controlled the destiny of men.

Did you know?

Over time, chronic hepatitis B virus and hepatitis C virus infections can progress to advanced liver disease, liver failure, and hepatocellular carcinoma. Unlike other forms, more than 80% of hepatitis C infections become chronic and lead to liver disease. When combined with hepatitis B, hepatitis C now accounts for 75% percent of all cases of liver disease around the world. Liver failure caused by hepatitis C is now leading cause of liver transplants in the United States.

Did you know?

According to the American College of Allergy, Asthma & Immunology, more than 50 million Americans have some kind of food allergy. Food allergies affect between 4 and 6% of children, and 4% of adults, according to the CDC. The most common food allergies include shellfish, peanuts, walnuts, fish, eggs, milk, and soy.

Did you know?

The average person is easily confused by the terms pharmaceutics and pharmacology, thinking they are one and the same. Whereas pharmaceutics is the science of preparing and dispensing drugs (otherwise known as the science of pharmacy), pharmacology is the study of medications.

Did you know?

Russia has the highest death rate from cardiovascular disease followed by the Ukraine, Romania, Hungary, and Poland.

For a complete list of videos, visit our video library