Complete the mcq:
Q1. Meagan Dubean manages a portfolio of 200 common stocks. Her staff classified the portfolio stocks by 'industry sector' and 'investment objective.'
Investment objective Industry Sector
Electronics Airlines Healthcare Total
Growth 84 21 35 140
Income 36 9 15 60
Total 120 30 50 200
Are "Healthcare" and "Income" independent and why or why not?
a. yes, because P(Income intersection Healthcare) 0
b. no, because P(Income intersection Healthcare) = P(Healthcare) ? P(Income)
c. yes, because P(Healthcare | Income) = P(Healthcare)
d. no, because P(Healthcare) not equal to P(Income)
Q2. If lambda is 3 occurrences per five minute time interval, the probability of getting 5 occurrences over a five minute interval is _______.
a. 0.1500
b. 0.0940
c. 0.1008
d. 0.0417
Q3. Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers. Accordingly, his staff recorded the waiting times for 64 randomly selected walk-in customers, and determined that their mean waiting time was 15 minutes and that the standard deviation was 4 minutes. The 95% confidence interval for the population mean of waiting times is ________.
a. 7.16 to 22.84
b. 14.06 to 15.94
c. 8.42 to 21.58
d. 13.88 to 16.12