HELP! Light bulb lifetime. Find the mean and median for the data in the following table...
O Light bulbifetime. Find the mean and median for the data in the following table Interval Frequency 2995 - 1995 2. Lite (Hours) of 50 Randomly selected Le Buba 8995-2005 995-10905 8 23 1.0995 - 1.199.5 1,1995-1,2905 5 The meanis The median is (Round to two decimal places if needed)
The lifetime of a certain brand of electric light bulb is known to have a standard deviation of 49 hours. Suppose that a random sample of 90 bulbs of this brand has a mean lifetime of 500 hours. Find a 90% confidence interval for the true mean lifetime of all light bulbs of this brand. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. What is the...
The lifetime of a certain brand of electric light bulb is known to have a standard deviation of 47 hours. Suppose that a random sample of 150 bulbs of this brand has a mean lifetime of 478 hours. Find a 90% confidence interval for the true mean lifetime of all light bulbs of this brand. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. What is the...
A light bulb manufacturer wants to compare the mean lifetimes of two of its light bulbs, model A and model B. Independent random samples of the two models were taken. Analysis of 11 bulbs of model A showed a mean lifetime of 1345 hours and a standard deviation of 102 hours. Analysis of 15 bulbs of model B showed a mean lifetime of 1389 hours and a standard deviation of 82 hours. Assume that the populations of lifetimes for each...
please answer neatly and correctly!
light bulb manufacturer wants to compare the mean lifetimes of two of its light bulbs, model A and model B. Independent random samples of the two models were taken. Analysis of 9 bulbs of model A showed a mean lifetime of 1234 hours and a standard deviation of 81 hours. Analysis of 15 bulbs of model B showed a mean lifetime of 1391 hours and a standard deviation of 110 hours. Assume that the populations...
Please answer neatly and correctly!
A light bulb manufacturer wants to compare the mean lifetimes of two of its light bulbs, model A and model B. Independent random samples of the two models were taken. Analysis of 15 bulbs of model A showed a mean lifetime of 1350 hours and a standard deviation of 102 hours. Analysis of 14 bulbs of model B showed a mean lifetime of 1384 hours and a standard deviation of 91 hours. Assume that the...
Suppose that the lifetimes of light bulbs are approximately normally distributed, with a mean of 57 hours and a standard deviation of 3.5 hours. With this information answer the following questions. (a) What proportion of light bulbs will last more than 62 hours? (b) What proportion of light bulbs will last 50 hours or less? (c) What proportion of light bulbs will last between 58 and 62 hours? (d) What is the probability that a randomly selected light bulb lasts...
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 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 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.