In: Statistics and Probability
Bicycles arrive at a bike shop in boxes. Before they can besold, they must be unpacked, assembled, and tuned(lubricated, adjusted, etc.). Based on past experience, the shop manager creates a model of how long this may take based on the assumptions that the times for each setup phase are independent, each phase follows a Normalmodel, and the means and standard deviations of the times in minutes are as shown in the table. Complete parts a) and b).
Phase Mean SD
Unpacking 3.5 .4
Assembly 22.1 2.8
Tuning 12.5 2.8
a) What are the mean and the standard deviation for the total bicycle setup time?
mean=38.1
SD=3.98
(Round to two decimal places as needed.)
b) A customer decides to buy one of the display models but wants a different color. The shop has one, still in the box. The manager says they can have it ready in half an hour. Do you think the bike will be set up and ready to go as promised? Explain.
(Round to four decimal places as needed.)
A.Yes, the probability that the bike will be ready in half an hour is ___________________
B.No, the probability that the bike will be ready in half an hour is __________________
The quarterly returns for a group of 68 mutual funds are well modeled by a Normal model with a mean of 5.6% and a standard deviation of 1.6%. Use the 68-95-99.7 Rule to find the cutoff values that would separate the following percentages of funds, rather than using technology to find the exact values.
a) the highest 50%
b) the highest 16%
c) the lowest 2.5%
d) the middle 68%