Question: 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

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 100 hours. A random sample of 64 light bulbs indicated a sample mean life of 350 hours.
a. Construct a 95% confidence interval estimate for the population mean life of light bulbs in this shipment.
b. Do you think that the manufacturer has the right to state that the light bulbs have a mean life of 400 hours? Explain.
c. Must you assume that the population light bulb life is normally distributed? Explain.
d. Suppose that the standard deviation changes to 80 hours. What are your answers in (a) and (b)?

Step by Step Solution

★★★★★

3.43 Rating (166 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer

Step: 1 Unlock

a 3255 37450 b No The manufacturer cannot support a claim that the bulbs last an average 400 hours B... View full answer

Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock

Step: 3 Unlock

Document Format (1 attachment)

854-M-S-H-T (4594).docx

120 KBs Word File

Students Have Also Explored These Related Statistics Questions!

Identification and discussion of relevant legal issues: Examination & analysis of information: Jerene, Joey and Xin are international students studying for a Hospitality and Tourism degree in...

The quality-control manager at a light bulb factory needs to determine whether the mean life of a large shipment of light bulbs is equal to 375 hours. The population standard deviation is 100 hours....

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 96 hours. A random sample of 64 light bulbs indicated...

7.15 Given a normal distribution with = 100 and = 10, if you select a sample of n= 25, what is the probability that X is a. less than 95? b. between 95 and 97.5? c. above 102.2? d. There is a 65%...

please only solve question D. 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 81 hours. A random...

)(a) The quality control manager at a light bulb factory needs to estimate the mean life of a large shipment of light bulbs. The process standard deviation is known to be 100 hours. A random sample...

Please help with last answer 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 98 hours. A random...

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 84 hours. A random sample of 49 light bulbs indicated...

P X mylab.pearson.com/Student/PlayerHomework.aspx?homeworkld=617360159&questionld=7&flushed=true&cld=6819319¢erwin=yes E Save The quality control manager at a light bulb factory needs to estimate...

Air at sonic conditions and static temperature and pressure of 500 K and 420 kPa, respectively, is to be accelerated to a Mach number of 1.6 by cooling it as it flows through a channel with constant...

What aspect of conjoint analysis makes it a more effective means of determining the value of a product feature than directly asking respondents how much they would pay for the feature?

23. An experiment has been conducted for four treatments with eight blocks. Complete the following analysis of variance table. Source of Variation Sum of Squares Degrees of Freedom Mean Square F...

Assume that the following conditions occur before the Christmas buying season: (1) the Toys 'R' Us chain underestimates demand for an electronic fad toy; (2) The Foot Locker shoe store chain...

We used the Lasagna Triers.xlsx file in this section to show how pivot tables can help explain which variables are related to the buying behavior of customers. Illustrate how the same information...

Solve problem 5 with pivot tables and create corresponding pivot charts. If you first find the quartiles of Salary and AmountSpent (by any method), is it possible to create the desired crosstabs by...

Solve problem 17 with pivot tables. However, find only means and standard deviations, not medians.

Discuss and explain the financial perfomance analysis, Balance Score Card performance measures and recommondations with overall conclusion for below available liquidity and profitability data of...

Here are data on two stocks, both of which have discount rates of 20% : a. What is the dividend payout ratio for each firm? Note: Enter your answers as a percent rounded to 2 declmal places. b. What...

E11-7 Computing Dividends on Preferred Shares and Analyzing Differences [LO3, LO4] The records of Hoffman Company reflected the following balances in the shareholders equity accounts at December 31,...