Lifetimes of AAA batteries are approximately normally distributed. A manufacturer wants to estimate the standard deviation of the lifetime of the AAA batteries it produces. A random sample of 17 AAA batteries produced by this manufacturer lasted a mean of 11 hours with a standard deviation of 2.5 hours. Find a 95% confidence interval for the population standard deviation of the lifetimes of AAA batteries produced by the manufacturer. Then complete the table below.Carry your intermediate computations to at least three decimal places. Round your answers to at least two decimal places.
What is the lower limit of the 95% confidence interval?
What is the upper limit of the 95% confidence interval?
Lifetimes of AAA batteries are approximately normally distributed. A manufacturer wants to estimate the standard deviation...
2 3 5 Lifetimes of AAA batteries are approximately normally distributed. A manufacturer wants to estimate the standard deviation of the lifetime of the AAA batteries it produces. A random sample of 15 AAA batteries produced by this manufacturer lasted a mean of 10.5 hours with a standard deviation of 2.4 hours. Find a 90% confidence interval for the population standard deviation of the lifetimes of AAA batteries produced by the manufacturer. Then complete the table below. Carry your intermediate...
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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...
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...
O CONFIDENCE INTERVALS AND HYPOTHESIS TESTING Confidence interval for the difference of population means: Use ... 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 10 bulbs of model A showed a mean lifetime of 1240 hours and a standard deviation of 89 hours. Analysis of 14 bulbs of model B showed a mean lifetime of 1253...
The batteries from a certain manufacturer have a mean lifetime of 850 hours, with a standard deviation of 90 hours. Assuming that the lifetimes are normally distributed, complete the following statements. (a) Approximately _______ of the batteries have lifetimes between 760 hours and 940 hours.(b) Approximately 95% of the batteries have lifetimes between _______ hours and _______ hours.
Records show that the lifetimes of batteries manufactured by a certain company have a mean of 620 hours and a standard deviation of 136. The company advertises that, currently, the standard deviation is less than 136, following some adjustments in production practices. A random sample of 23 recently produced batteries from this company had a mean lifetime of 618 hours and a standard deviation of 96. Is there enough evidence to conclude, at the 0.05 level of significance, that the...
Records show that the lifetimes of batteries manufactured by a certain company have a mean of 620 hours and a standard deviation of 136. The company advertises that, currently, the standard deviation is less than 136, following some adjustments in production practices. A random sample of 23 recently produced batteries from this company had a mean lifetime of 618 hours and a standard deviation of 96. Is there enough evidence to conclude, at the 0.05 level of significance, that the...
The scores on an examination in biology are approximately normally distributed with mean 500 and an unknown standard deviation. The following is a random sample of scores from this examination. 419, 455, 479, 535, 540, 607 Find a 99% confidence interval for the population standard deviation. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your answers to at least two decimal places (If necessary, consult a list of formulas-) What is the...
Suppose that the lifetimes of light bulbs are approximately normally distributed. A random sample with 38 light bulbs was obtained with a mean of 60 hours and a standard deviation of 4.5 hours. With this information, answer the following questions. To estimate the population mean, what is the Standard Error? To estimate the population mean at 95% C.L., what is the Margin of Error? At a 96% C.L., if the researcher wants to limit the margin of error within 0.5...