Business, 25.06.2021 18:30 liltinyhead

A design engineer wants to construct a sample mean chart for controlling the service life of a halogen headlamp his company produces. He knows from numerous previous samples that this service life is normally distributed with a mean of 500 hours and a standard deviation of 20 hours. On three recent production batches, he tested service life on random samples of four headlamps, with these results: Sample Service Life (hours)
1 495 500 505 500
2 525 515 505 515
3 470 480 460 470
1) What is the sample mean service life for sample 2?
A. 495 Hours
B. 460 Hours
C. 500 Hours
D. 515 Hours
E. 525 Hours
2) What is the mean of the sampling distribution of sample means when the service life is in control?
A. 250 Hours
B. 470 Hours
C. 515 Hours
D. 495 Hours
E. 500 Hours
3) What is the standard deviation of the sampling distribution of sample means for whenever service life is in control?
A. 20 Hours
B. 10 Hours
C. 11.55 Hours
D. 5 Hours
E. 6.67 Hours
4) If he uses upper and lower control limits of 520 and 480 hours, what is his risk (alpha) of concluding that service life is out of control when it is actually under control (Type I error)?
A. 0.0026
B. 0.3174
C. 0.6826
D. 0.0456
E. 0.9544
5) If he uses upper and lower control limits of 520 and 480 hours, on what sample(s) (if any) does service life appear to be out of control?
A. sample 1
B. sample 2
C. sample 3
D. both samples 2 and 3
E. all samples are in control

Answers: 3

Show answers

Answers

Answer from: sophie5988

1) 515 hours ( D )

2) 495 hours ( D )

3) 10 hours ( B )

4) 0.0456 ( D )

5) sample 3 ( C )

Explanation:

Standard deviation = 20 hours

Mean = 500 hours

1) Determine the sample mean service life for sample 2

Sample mean sample service life of sample 2 = Average of service life of sample 2

= ( 525 + 515 + 505 + 515 ) / 4

= 2060 / 4 = 515

2) Calculate the mean of sampling distribution of sample means

∑ mean service life samples / 3 ( 1 )

sample 1 = (495 + 500 + 505 + 500 ) / 4 = 500

sample 2 = ( 525 + 515 + 505 + 515 ) / 4 = 515

sample 3 = (470 + 480 + 460 + 470) = 470

back to equation 1

= ( 500 + 515 + 470 ) / 3 = 495

3) Determine STD of sampling distribution of sample means

Std = 20

n = 4

∴ std of sampling distribution = 20 / √4 = 10 hours

4) calculating the risk alpha

upper control ( UCL ) = 520 , lower control ( LCL ) = 480

mean = 500

Z value for upper control = ( 520 - 500) / 10 = 2

Z value for lower control = ( 480 - 500 ) / 10 = -2

confidence level of -2 and 2 ( using z-table ) = 0.9544

∴ risk alpha = 1 - 0.9544 = 0.0456

5) Service life appears to be out of control in ; sample 3

UCL = 520 , LCL = 480

Because mean value of sample 3 = 470 lies outside the lower control limit

Answer from: Quest

Renting provides greater flexibility but can lead to higher costs in the long term.answer: b) or the second option.

Answer from: Quest

The business cycle is the periodic but irregular up-and-down movement in economic activity, measured by fluctuations in real gross domestic product (gdp) and other macroeconomic variables. a business cycle is typically characterized by four phases—recession, recovery, growth, and decline—that repeat themselves over time. economists note, however, that complete business cycles vary in length. the duration of business cycles can be anywhere from about two to twelve years, with most cycles averaging six years in length. some business analysts use the business cycle model and terminology to study and explain fluctuations in business inventory and other individual elements of corporate operations. but the term "business cycle" is still primarily associated with larger (industry-wide, regional, national, or even international) business trends.

Another question on Business

Business, 22.06.2019 03:30

Lindon company is the exclusive distributor for an automotive product that sells for $30.00 per unit and has a cm ratio of 30%. the company’s fixed expenses are $162,000 per year. the company plans to sell 20,200 units this year. required: 1. what are the variable expenses per unit? (round your "per unit" answer to 2 decimal places.) 2. what is the break-even point in unit sales and in dollar sales? 3. what amount of unit sales and dollar sales is required to attain a target profit of $72,000 per year? 4. assume that by using a more efficient shipper, the company is able to reduce its variable expenses by $3.00 per unit. what is the company’s new break-even point in unit sales and in dollar sales? what dollar sales is required to attain a target profit of $72,000?

Answers: 2

Answer

Business, 22.06.2019 08:20

How much does a neurosurgeon can make most in canada? give me answer in candian dollar

Answers: 1

Answer

Business, 22.06.2019 18:50

Retirement investment advisors, inc., has just offered you an annual interest rate of 4.4 percent until you retire in 40 years. you believe that interest rates will increase over the next year and you would be offered 5 percent per year one year from today. if you plan to deposit $13,000 into the account either this year or next year, how much more will you have when you retire if you wait one year to make your deposit?

Answers: 3

Answer

Business, 23.06.2019 01:50

Consider a firm with a contract to sell an asset for $149,000 four years from now. the asset costs $85,000 to produce today. a. given a relevant discount rate of 14 percent per year, calculate the profit the firm will make on this asset. (a loss should be indicated by a minus sign. do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) b. at what rate does the firm just break even?

Answers: 3

Answer

You know the right answer?

A design engineer wants to construct a sample mean chart for controlling the service life of a halog...

Questions