The life in hours of a 75-watt light bulb is known to be normally distributed with...

Question

Question

The life in hours of a 75-watt light bulb is known to be normally distributed with...

The life in hours of a 75-watt light bulb is known to be normally distributed with σ = 25 hours. Suppose that you wanted the total width of the two-sided confidence interval on the mean life to be six hours at 95% confidence. What sample size should be used?

math Statistics-And-Probability

Add a comment Improve this question Transcribed image text

Answer 1

✔ Recommended Answer

Answer #1

Soutin!. Given that Standard deviation o =25 margin of omor : 6:3 Zap = 1.96 simple size ana (tap toe - (196707) - 267 sumple

Add a comment

Answer 2

Similar Homework Help Questions

The life in hours of a 75-watt light bulb is known to be normally distributed with...

The life in hours of a 75-watt light bulb is known to be normally distributed with σ = 27 hours. A random sample of 20 bulbs has a mean life of x Overscript bar EndScripts = 1015 hours. Suppose that we wanted the total width of the two-sided confidence interval on mean life to be six hours at 95% confidence. What sample size should be used? Round up the answer to the nearest integer.
The life in hours of a 75-watt light bulb is known to be normally distributed with...

The life in hours of a 75-watt light bulb is known to be normally distributed with = 23 hours. A random sample of 20 bulbs has a mean life of X= 1011 hours. Suppose that we wanted the margin of error in estimating the mean life from the two-sided confidence interval to be five hours at 95% confidence. What sample size should be used? Round up the answer to the nearest integer. Statistical Tables and Charts
= 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...

Construct the 95% confidence interval for mean life

a) The life hours of a 75-watt light bulb is known to be approximately normally distributed with standard deviation   25 hours. A random sample of 25 bulbs has a mean life of x  1050 hours.Construct the 95% confidence interval for mean life, .
Let X be the length of life of a 60-watt light bulb manufactured by a certain...

Let X be the length of life of a 60-watt light bulb manufactured by a certain company. If a random sample of 25 units is tested until they burn out, yielding a sample mean of x = 1478 hours and s 2 x = 1296, compute a confidence 95 % -confidence interval for the mean and the variance.
25> Consider a variable known to be Normally distributed with unknown mean μ and known standard...

25> Consider a variable known to be Normally distributed with unknown mean μ and known standard deviation σ-10. (a) what would be the margin of error of a 95% confidence interval for the population mean based on a random sample size of 25? The multiplier for a z confidence interval with a 95% confidence level is the critical value z. 1.960. (Enter your answer rounded to three decimal places.) margin of error 25 (b) What would be the margin of...

The quality control manager at a light bulb factory needs to estimate the mean life of...

The quality control manager at a light bulb factory needs to estimate the mean life of a large shipment of light bulbs. The standard deviation is 92 hours. A random sample of 64 light bulbs indicated a sample mean life of 360 hours. Complete parts (a) through (d) below. that the lightbulbs have a mean life of 410 hours. c. Must you assume that the population light bulb life is normally distributed? Explain. O A. Yes, the sample size is...
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 mean life of a particular brand of light bulb is 1200 hours and the standard...

The mean life of a particular brand of light bulb is 1200 hours and the standard deviation is 75 hours. Tests show that the life of the bulb is approximately normally distributed. What is the range of hours that approximately 68% of the bulbs will last?

Sam’s Long Life 75-watt light bulbs are designed to have a life of 1,125 hours with...

Sam’s Long Life 75-watt light bulbs are designed to have a life of 1,125 hours with tolerance of ± 210 hours. A recent representative sample from the process that makes these light bulbs revealed a mean of 1,050 hours, with a standard deviation of 55 hours. Compute Compute the process capability ratio and the process capability index, and comment on the overall capability of the process Explain to what extent the process for producing Sam’s Long Life 75-watt light bulbs...

The life in hours of a 75-watt light bulb is known to be normally distributed with...

Homework Answers