QUESTION 11 Light bulbs are found to have a mean life of 800. The standard deviation...
Light bulbs are found to have a mean life of 800 hours. The standard deviation is 160. A sample of 400 is chosen. Find the probability that 798 < x < 802
QUESTION 5 Tires are found to have a mean life of 800 hours. The standard deviation is 50. A sample of 100 is chosen. Find the probability that 40 800 < x < 812
1. A population has a mean of 60 and a standard deviation of 30. Samples of size 16 are randomly selected. Calculate the standard deviation of the sample distribution X. 2. Samples of size 16 are drawn from a population. the sampling distribution for X has a standard deviation of 0.25. Find the standard deviation of the population. 4. Tires are found to have a mean life of 40,000 miles. The standard deviation is 8000. A sample of 400 is...
An electrical firm manufactures light bulbs that have a length life with normal distribution, and mean equal to 800 hours, and a variance of 9. Find the probability that a random sample of 38 light bulbs will have a sample variance S2 greater than 9.97. Find the probability that a random sample of 32 light bulbs will have a sample variance s? of at most 4.2.
An electrical firm manufactures light bulbs that have a length life with normal distribution, and mean equal to 800 hours, and a variance of 8. Find the probability that a random sample of 29 light bulbs will have a sample variance S2 between 7.81 and 16.25.
A company manufactures light bulbs. The company wants the bulbs to have a mean life span of 991 hours. This average is maintained by periodically testing random samples of 16 light bulbs. If the t-value falls between -t0.95 and t0.95, then the company will be satisfied that it is manufacturing acceptable light bulbs. For a random sample, the mean life span of the sample is 999 hours and the standard deviation is 22 hours. Assume that life spans are approximately...
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 life of light bulbs is distributed normally. The standard deviation of the lifetime is 20 hours and the mean lifetime of a bulb is 570 hours. Find the probability of a bulb lasting for at least 597 hours. Round your answer to four decimal places.
A manufacturer claims his light bulbs have a mean life of 2000 hours. A consumer group wants to test if their light bulbs do not last as long as the manufacturer claims. They tested a random sample of 210 bulbs and found them to have a sample mean life of 1980 hours and a sample standard deviation of 50 hours. Assess the manufacturer's claim. a) What is the null hypothesis? Ou = 2000 O x = 2000 Ox< 2000 Ou...
A manufacturer claims his light bulbs have a mean life of 1800 hours. A consumer group wants to test if their light bulbs do not last as long as the manufacturer claims. They tested a random sample of 270 bulbs and found them to have a sample mean life of 1790 hours and a sample standard deviation of 60 hours. Assess the manufacturer's claim. a) What is the null hypothesis? Correct: y = 1800 Incorrect x = 1800 Incorrect x...