DSCI Mock Test

Infeasibility means that the number of solutions to the linear programming models that satisfies all the problem's constraints is at least 1. 0. an infinite number. at least 2.

0

Daily demand for newspapers for the last 10 days has been as follows (listed from oldest to newest): 12, 13, 16, 15, 12, 18, 14, 12, 13, 15. Forecast sales for the next day (i.e. day 11) using a two-day moving average. 14 15 13 28 none of the above

14

Consider a project that has an expected completion time of 30 weeks and a standard deviation of 6 weeks. What is the probability that the project will be take more than 42 weeks? (Round answer) 68% 98% 2% 16% not enough information

2%

Calculate MAD for the following forecast versus actual sales figures. Forecast Actual 100 95 110 108 120 123 130 130 2.5 10 9.5 38

2.5

The annual demand of a certain item is 5400 units and the computed EOQ is 900 units. How many orders do they have to make per year? 1 3 4 6

5400/900=6

At a local fast food joint, cars arrive randomly at a rate of 12 every 30 minutes. Service times are random (exponential) and average 2 minutes per arrival. The average time in the queue for each arrival is 2 minutes 4 minutes 6 minutes 8 minutes 10 minutes

8 minutes

The following is a payoff table giving profits for various situations. What decision would an optimistic person make?

Alternative 2

The annual demand for a product has been projected at 2,000 units. This demand is assumed to be constant throughout the year. The ordering cost is $20 per order, and the holding cost is 20 percent of the purchase cost. Currently, the purchase cost is $40 per unit. There are 250 working days per year. Whenever an order is placed, it is known that the entire order will arrive on a truck in 6 days. How many units should the company order each time an order is placed if the company wishes to minimize total inventory cost? 100 200 250 500 none of the above

Answer a: 100 explanation: Annual demand, D=2000Order cost or setup cost, S$20.00item cost$40.00holding cost percent20%holding cost per year, H=holding cost percent*item cost$8.00Economic Order quantity, Q=

Given an activity's optimistic, most likely, and pessimistic time estimates of 4, 14, and 18 days respectively, compute the PERT expected activity time for this activity. a. 14 b. 12 c. 11 d. 13

Expected activity time = (Opt_time + 4 * Likely_time + Pess_time) / 6 = (4 + 4 * 14 + 18 ) / 6 = 78 / 6 = 13

On a practical note-if we are using waiting line analysis to study cars passing through a single tollbooth, reneging is probably not an issue. True False

FALSE

Consider the following linear programming problem: Maximize 4X + 10Y Subject to: 3X + 4Y ≤ 480 4X + 2Y ≤ 360 all variables ≥ 0 The feasible corner points are (48,84), (0,120), (0,0), (90,0). What is the maximum possible value for the objective function? a. 1032 b. 1200 c. 360 d. 1600 e. None of the above

We need to maximize 4X + 10Y For (48, 84), objective function = 4 * 48 + 10 * 84 = 1032 For (0, 120), objective function = 4 * 0 + 10 * 120 = 1200 For (0, 0), objective function = 4 * 0 + 10 * 0 = 0 For (90 , 0), objective function = 4 * 90 + 10 * 0 = 360 So, the maximum possible value for the objective function = 1200 (ans

A suburban specialty restaurant has developed a single drive-thru window. Customers order, pay, and pick up their food at the same window. Arrivals follow a Poisson distribution while service times follow an exponential distribution. If the average number of arrivals is 6 per hour and the service rate is 2 every 15 minutes, what proportion of the time is the server busy (utilized)? 0.25 0.50 0.75 2.25

arrival rate lamda,k =6 per hour service rate,u = 2 every 15 minutes u = 8 per hour p = k/u = 0.75 the average number of customers waiting in line behind the person being served is = (p^2)/(1-p) = 2.25

A constraint that does not affect the feasible region is a a. non-negativity consraint b. redundant constraint c. standard constraint d. slack constraint

b

Which of the following statements is true about r2? a. It is also called the coefficient of correlation. b. It is also called the coefficient of determination c. It represents the percent of variation in X that is explained by Y. d. It represents the percent of variation in the error that is explained by Y. e. It ranges in value from -1 to + 1.q

b

Which of the following is a general rule for crashing activities? Crash only non-critical activities Crash activities with zero slack. Crash activities with the greatest number of predecessors. Crash the path with the fewest activities.

crash activities with zero slack

The variance of the project completion time is equal to the sum of the variances of all the activities. True False

false

The critical path of a network is the shortest time path through the network path with the fewest activities path with the most activities. longest time path through the network

longest time path through the network

At an automatic car wash, cars arrive randomly at a rate of 7 cars every 30 minutes. The car wash takes exactly 4 minutes. On average, what would the length of the line be? 8.171 7.467 6.533 0.467 none of the above

none of the above

Which of the following factors is (are) not included in ordering cost? bill paying obsolescence purchasing department overhead costs inspecting incoming inventory developing and sending purchase orders

obsolesecense

The term queue discipline describes the degree to which members of the queue renege. sequence in which members of the queue arrived. degree to which members of the queue are orderly and quiet. sequence in which members of the queue are serviced. all of the above

sequence in which members of queue are serviced

An M│M│3 model has Poisson arrivals, exponential service times, and two channels. True False

true

EVPI (Expected Value of Perfect Information) is a measure of the maximum value of additional information. a. True b. False

true

One difficulty in waiting line analysis is that it is sometimes difficult to place a value on customer waiting time. True False

true

Slack is the time an activity can be delayed without impacting the completion time of the project. True False

true

The set of solution points that satisfies all of a linear programming problem's constraints simultaneously is defined as the feasible region in graphical linear programming. True False

true

When looking at the arrivals at the ticket counter of a movie theater, we can assume an unlimited queue. True False

true