Woodworkers Alex and Brandon make precision pieces for toys. Each toy requires four 8-inch long sticks. Alex cuts four sticks one at time, and their lengths are independent. Alex’s sticks have mean length 8 inches with a standard deviation 0.15 inches. Brandon clamps four sticks together and cuts them all at once, so that they all have the same length. Brandon’s sticks also have a mean length of 8 inches with a standard deviation of 0.15 inches.
a. Alex’s four sticks are laid end-to-end. What is the mean of the total length? What is the standard deviation of the total length?
b. Brandon’s four sticks are laid end-to-end. What is the mean of the total length? What is the standard deviation of the total length?
c. Four sticks, two from Alex and two from Brandon, are laid end-to-end. What is the mean of the total length? What is the standard deviation of the total length?
Let 
denote the lengths of Alex’s sticks. Then 
are independent with mean 8 and standard deviation 15. Let Y denote the length of Brandon’s sticks. Then Y has mean 8 and standard deviation 0.15. Let A denote the total length of Alex’s sticks, let ? denote the total length of Brandon’s sticks, and let C denote the length of two sticks from Alex plus two sticks from Brandon.
You might also like to view...
Explain why gypsum board is an excellent material for providing fire resistance in building assemblies.
What will be an ideal response?
All magnets have three poles.
Answer the following statement true (T) or false (F)
How can you tell when a filter drier is stopped up?
A) You will see the accumulated debris in the filter's sight glass. B) It will have a pressure drop of more than 2 psi across the filter. C) The "plugged filter" flag will pop out of the leaving flare port. D) You will hear a whistling sound in the filter.
The 1's-complement of the binary number 0101101012 is:
A) 011001010 B) 101001010 C) 101001000 D) 101110101