The mean life of a random sample of 25 tires of a certain brand is 28,000mi....
The mean life of a random sample of 25 tires of a certain brand is 28,000mi.
(a) If the standard deviation of the population is known to be 3500mi, what is the twosided 90% confidence on the mean?
(b) If the variance of the population is not known and the standard deviation of the random sample is 3500mi, what is the two-sided 90% confidence interval?
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The mean life of a random sample of 25 tires of a certain brand
is 28,000mi....
6. You measure the lifetime (in miles of driving use) of a random sample of 25...
6. You measure the lifetime (in miles of driving use) of a random sample of 25 tires of a certain brand. The sample mean is 65,750 miles. Suppose that the lifetimes for tires of this brand follow a normal distribution, with unknown mean μ and standard deviation σ = 4,500 miles. Find a 95% confidence interval for the population mean.
2. Let u be the mileage of a certain brand of tire. A sample of n = 20 tires is taken at random, resulting in the sampl...
2. Let u be the mileage of a certain brand of tire. A sample of n = 20 tires is taken at random, resulting in the sample mean X = 32, 215 and sample variance s2 = 3, 116. Assuming that the distribution is normal, find a 99 percent confidence interval for u.
The lifetime of a certain brand of battery is known to have a standard deviation of...
The lifetime of a certain brand of battery is known to have a standard deviation of 19.8 hours. Suppose that a random sample of 100 such batteries has a mean lifetime of 33.3 hours. Based on this sample, find a 90% confidence interval for the true mean lifetime of all batteries 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. 0 What is the...
Show all work S. The tread life a certain brand of tires is known to be...
Show all work
S. The tread life a certain brand of tires is known to be normally distributed with a mean of 50,000 miles and a standard deviation of 4,500 miles a) Determine the probability that a randomly selected tire will last longer than 62,000 miles ANSWER b) The company wishes to set the warranty so that warranty mileage be? only 3% of the tires will need to be replaced, what should the ANSWER
The lifetime of a certain brand of electric light bulb is known to have a standard...
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...
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...
6. (A) The information obtained from a random sample of 1,600 users of the Arctic Power Tires yielded a mean useful life...
6. (A) The information obtained from a random sample of 1,600 users of the Arctic Power Tires yielded a mean useful life of 251,000kms and a standard deviation of 30,000kms. (a) Test the hypothesis that the mean lifetime L of this make of tire is not significantly different from 250,000kms. Let o = 0.05. Assume that the useful life L is a normally distributed random variable. (b) The following is an interesting and useful way of finding an approximate (1-—o)100%...
= 25 hours. A random sample of 22 bulbs The life in hours of a 75-watt...
= 25 hours. A random sample of 22 bulbs The life in hours of a 75-watt light bulb is known to be normally distributed with has a mean life of K = 1014 hours. (a) Construct a 95% two-sided confidence interval on the mean life. Round your answers to the nearest integer (e.g. 9876). (b) Construct a 95% lower-confidence bound on the mean life. Compare the lower bound of this confidence interval with the one in part (a). Round your...
Suppose that a random sample of 95 tyres of a certain brand lasted a mean of...
Suppose that a random sample of 95 tyres of a certain brand lasted a mean of 21,431 kilometres with a standard deviation of 1295 kilometres. At the 0.01 level of significance, test the null hypothesis that the mean life of this brand of tyre is 22,000 kilometres against the alternative hypothesis that this figure is too high. [5 marks]
a sample of 16 small bags of the same brand of candies was selected. assume the...
a sample of 16 small bags of the same brand of candies was selected. assume the population distribution of bag weights is normal. the weight of each bag was then recorded. the mean weight was two ounces with a standard deviation of 0.12 ounces. the population standard deviation is known to be 0.1 ounce. a) construct a 90% confidence interval for the population mean weight of the candies. i. state the confidence interval ii.sketch the graph iii.calculate the error bound
2. Let u be the mileage of a certain brand of tire. A sample of n = 20 tires is taken at random, resulting in the sample mean X = 32, 215 and sample variance s2 = 3, 116. Assuming that the distribution is normal, find a 99 percent confidence interval for u.
The lifetime of a certain brand of battery is known to have a standard deviation of 19.8 hours. Suppose that a random sample of 100 such batteries has a mean lifetime of 33.3 hours. Based on this sample, find a 90% confidence interval for the true mean lifetime of all batteries 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. 0 What is the...
Show all work
S. The tread life a certain brand of tires is known to be normally distributed with a mean of 50,000 miles and a standard deviation of 4,500 miles a) Determine the probability that a randomly selected tire will last longer than 62,000 miles ANSWER b) The company wishes to set the warranty so that warranty mileage be? only 3% of the tires will need to be replaced, what should the ANSWER
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...
= 25 hours. A random sample of 22 bulbs The life in hours of a 75-watt light bulb is known to be normally distributed with has a mean life of K = 1014 hours. (a) Construct a 95% two-sided confidence interval on the mean life. Round your answers to the nearest integer (e.g. 9876). (b) Construct a 95% lower-confidence bound on the mean life. Compare the lower bound of this confidence interval with the one in part (a). Round your...
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