Light bulbs with a stated mean lifetime of 750 hours have been stored in a warehouse...
Light bulbs with a stated mean lifetime of 750 hours have been stored in a warehouse for years . A sample of 10 of these bulbs is selected at random and destructively tested . The results of this sample gave a mean of 720 hours with a standard deviation of 40 hours . You wish to test whether prolong storage has significantly reduced the life expectancy of these light bulbs . You can assume that bulb lifetime is normally distributed. What is the correct p -value of this test ?
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Light bulbs with a stated mean lifetime of 750 hours
have been stored in a warehouse...
The life of light bulbs is distributed normally. The variance of the lifetime is 400400 and...
The life of light bulbs is distributed normally. The variance of the lifetime is 400400 and the mean lifetime of a bulb is 600600 hours. Find the probability of a bulb lasting for at most 633633 hours. Round your answer to four decimal places.
The life of light bulbs is distributed normally. The variance of the lifetime is 625 and...
The life of light bulbs is distributed normally. The variance of the lifetime is 625 and the mean lifetime of a bulb is 510 hours. Find the probability of a bulb lasting for at most 527 hours. Round your answer to four decimal places.
The life of light bulbs is distributed normally. The variance of the lifetime is 625 and...
The life of light bulbs is distributed normally. The variance of the lifetime is 625 and the mean lifetime of a bulb is 570 hours. Find the probability of a bulb lasting for between 532 and 599 hours. Round your answer to four decimal places.
The life of light bulbs is distributed normally. The standard deviation of the lifetime is 15...
The life of light bulbs is distributed normally. The standard deviation of the lifetime is 15 hours and the mean lifetime of a bulb is 580 hours. Find the probability of a bulb lasting for at least 590 hours. Round your answer to four decimal places.
The lifetime of traditional light bulbs measured in hours is known to be normally distributed with...
The lifetime of traditional light bulbs measured in hours is known to be normally distributed with μ=100 and σ=20. What is the probability that a randomly selected traditional light bulb will have a lifetime of 125 hours or longer? You need to use a normal distribution table. Find the nearest answer. a. 4.006% b. 22.663% c. 10.565% d. 77.337% e. 89.435%
ECON 15B 3. A package of light bulbs promises an average life of more than 750...
ECON 15B 3. A package of light bulbs promises an average life of more than 750 hours per bulb. A consumer group did not believe the claim and tested a sample of 40 bulbs. The average lifetime of these 40 bulbs was 740 hours with 13 = 30 hours. The manufacturer responded that its claim was based on testing hundreds of bulbs. a. If the consumer group and manufacturer both make 95% confidence intervals for the population's average lifetime, whose...
1. An electric firm manufactures light bulbs that have a lifetime, X, that is approximately norma...
1. An electric firm manufactures light bulbs that have a lifetime, X, that is approximately normally distributed with a standard deviation of 100 hours. Prior experience leads the firm to establish that the mean of X (or mean lifetime), say , follows a normal distribution with mean 140-800 hours and standard deviation σ0 10 hours. If a random sample of 25 bulbs examined turns out an average lifetime of 780 hours, solve the following. (a) Find a 95% Bayesian estinate...
The life expectancy of a particular brand of light bulbs is normally distributed with a mean of 1500 hours and a standard deviation of 75 hours. What is the probability that a bulb will last between 1500 and 1650 hours?
The life expectancy of a particular brand of light bulbs is normally distributed with a mean of 1500 hours and a standard deviation of 75 hours. What is the probability that a bulb will last between 1500 and 1650 hours?
The lifetime of a particular type of light bulb are approximately normally distributed with a mean...
The lifetime of a particular type of light bulb are approximately normally distributed with a mean of 1200 hours and a standard deviation of 140 hours. At what number of hours should the warranty lifetime be set so that only 2% of bulbs must be replaced under warranty?
Two light bulbs, have exponential lifetime where expected lifetime for bulb A is 500 hours and ex...
Two light bulbs, have exponential lifetime where expected lifetime for bulb A is 500 hours and expected lifetime for bulb B is 200 hours. a) What is the expected time until bulb A or bulb B malfunctions ? b) What is the probability that bulb A malfunctions before bulb B ?
The life of light bulbs is distributed normally. The variance of the lifetime is 625 and the mean lifetime of a bulb is 570 hours. Find the probability of a bulb lasting for between 532 and 599 hours. Round your answer to four decimal places.
ECON 15B 3. A package of light bulbs promises an average life of more than 750 hours per bulb. A consumer group did not believe the claim and tested a sample of 40 bulbs. The average lifetime of these 40 bulbs was 740 hours with 13 = 30 hours. The manufacturer responded that its claim was based on testing hundreds of bulbs. a. If the consumer group and manufacturer both make 95% confidence intervals for the population's average lifetime, whose...
1. An electric firm manufactures light bulbs that have a lifetime, X, that is approximately normally distributed with a standard deviation of 100 hours. Prior experience leads the firm to establish that the mean of X (or mean lifetime), say , follows a normal distribution with mean 140-800 hours and standard deviation σ0 10 hours. If a random sample of 25 bulbs examined turns out an average lifetime of 780 hours, solve the following. (a) Find a 95% Bayesian estinate...
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