Question

LPeint each 1) Over a 6 month period the average stock prices for Nike is $55.62 and Under Amour is $24.86. The standard devistions are $5.10 for Nike apd $3 60 for Under Amour. Over the 6 months period, which stoek exhibits greater variability? (Prove statistically 2) Below are ticket prices for an event. Are the ticket prices normally distributed or skewed (Prove statistically) $4, S18, S11, $7, $7, $10, $5, $33, $9, $12, $3, $11, S10, S6, S16, S37, S15, S18, S10, S31. 3) The American Sleep Association indicated that on average a child should get 7.5 hours of sleep per day with a standard deviation of 7 hour per day. The American Sleep Association recommends 8 hours per day. Assume for the study that was done, the data gathered was normal. (a) Calculate the percentage of children that get between 6.5 and 8.0 hours of sleep per day. (b) Calculate percentage of children that get more than 7 hours of sleep. 4) Matthews, Young and Associates, a management consulting firm, has four types of professional on its staff: Managing consultants, senior associates, field staff, and office staff. Average rates charged to consulting elients for the work of each of these professional categories are $75/hour, $40/hour, $30/hour, and $15/hour. Office records indicate the following number of hours billed last year in each category: 8,000, 14,000, 24,000, and 35,000. If Matthews, Young is trying to come up with an average billing rate for estimating client charges for next year, what do you think is an appropriate rate? (prove statistically)

Answer 1

1. For Nike:

Mean = $55.62

Standard deviation = $5.10

95% confidence interval is:

Lower bound = 55.62 - 2*5.10 = 45.42

Upper bound = 55.62 + 2*5.10 = 65.82

The 95% confidence interval is between 45.42 and 65.82.

For Under Armour:

Mean = $24.86

Standard deviation = $3.60

95% confidence interval is:

Lower bound = 24.86 - 2*3.60 = 17.66

Upper bound = 24.86 + 2*3.60 = 32.06

The 95% confidence interval is between 17.66 and 32.06.

The 95% confidence interval is wider for Nike than Under Armour. Therefore, Nike's stock exhibits greater variability.