Refer to Exercise 5. Additional pieces of yarn will be sampled in order to improve the precision of the confidence interval. Which would increase the precision the most: sampling 50 additional pieces of yarn from the old batch, 50 additional pieces from the new batch, or 25 additional pieces from each batch?
What will be an ideal response?
The standard deviation for the difference between the means is 
Estimate 
If 50 pieces of yarn are sampled from the old batch, then 
= 175 and 
= 75.
The standard deviation for the difference between the means is then 
If 50 pieces of yarn are sampled from the new batch, then = 125 and = 125.
The standard deviation for the difference between the means is then 
If 25 pieces of yarn are sampled from each batch, then = 150 and = 100.
The standard deviation for the difference between the means is then 
Therefore sampling 50 additional pieces from the new batch increases the precision the most.
You might also like to view...
Compared with most 17th- century Europeans, Americans lived in
A. relative poverty. B. larger cities. C. affluent abundance. D. a more rigid class system. E. more primitive circumstances.
What is the radius that is required on piece A3?
Review drawing number 523409B0A and then answer the question.
An engine fails to reach normal operating temperature. Which is the most likely fault?
A) Wrong antifreeze coolant B) Defective thermostat C) Low coolant level D) Partially clogged radiator
A gear of 10 teeth turning 100 rpm is driving a gear of 40 teeth. Find the rpm of the driven gear.
A. 20 B. 25 C. 30 D. 40