Economics Homework
Homework 4 (100 pts)
1. (10 pts) Ross Systems in considering four projects A, B, C and D that have
risks associated with the producing benefits. Based on the information given in
the table below, which project is more desirable for the company?
2. a) (10 pts) Find the expected EUAW from the cost data provided in the table
below for an equipment being considered at John Case Inc. in Dickson,
Tennessee. Because of the uncertainty of technology being used in this
equipment, it has not been possible to get the initial cost accurately. The annual
benefit, however, is estimated to be $20,000 with a possible equipment life of 5
years. The salvage value is expected to be 10% of the initial cost. MARR =8%
First Cost, $ $50,000 $80,000 $100,000 $125,000
Probability 0.25 0.35 0.30 0.10
b) (10 pts) Determine the associated risk measure in this equipment investment
in terms of standard deviation.
3. (10 pts) Three estimators at Tech Engineering have come up with the
estimates of cash flows as shown in the table below for a project with a life of
10 years. Compute the expected NPW at 20%.
Data Estimator I Estimator II Estimator III
First Cost, $ 5,000 8,750 7,500
Benefits /Year, $ 3,750 4,000 3,000
Salvage Value 1,750 1,000 5,000
4. (10 pts) A sample of automobile batteries is tested. The distribution of
battery life is found to be mound-shaped and symmetrical (normal) with a mean
life of 36 months and a standard deviation of six months. The batteries carry
a 24-month guarantee. What percent of batteries will fail in less than 24 months?
5. (15 pts) An investment of $18,000 is expected to generate annual revenue
of $8,000 throughout life of the investment. The risk is based the life of the
investment. The estimate of probabilities for the duration of the investment is
given in the table below. No matter what the life of the investment might be,
Project A Project B Project C Project D
EUAW Prob. EUAW Prob. EUAW Prob. EUAW Prob.
$2,000 0.2 $3,000 0.1 -$5,000 0.2 $4,000 0.4
$1,500 0.5 -$2,500 0.4 $6,500 0.5 $2,500 0.3
$3,000 0.3 $3,500 0.5 $1,000 0.3 -$2,000 0.3
there will be no salvage value. Using a value of 15% MARR, compute the risk
(standard deviation) associated with this investment.
6. (10 pts) A robot has just been installed at a cost of $81,000. It will have no
salvage value at the end of its useful life. Please provide your answer using
EXCEL.
Savings per year Probability Useful life (years) Probability
$18,000 0.2 12 1/6
$20,000 0.7 5 2/3
$22,000 0.1 4 1/6
(a) What is the joint probability distribution for savings per year and useful
life?
(b) Define optimistic, most likely, and pessimistic scenarios by using both
optimistic, both most likely, and bot pessimistic estimates. What is the rate
of return for each scenario?
7. (15 pts) For the data in Problem 6:
(a) What are the expected savings per year, life, and corresponding rate of
return for the expected values?
(b) Compute the rate of return for each combination of savings per year and
life. What is the expected rate of return (Excel can be used in (b))?
(c) Do the answers for (a) and (b) match? Why or why not?
8. (10 pts) The tree below has probabilities (in the brackets) after each chance
node and PW values for each terminal node. What decision should be
made? What is the expected value?
D1
Pick A
C1
H(0.4)
D2
Pick A1
C3
H(0.4)
12,000
L(0.6)
8100
Pick A2
10,000L(0.6)
4000
Pick B
C2
H(0.4)
9000
L(0.6)
5000
Life, Years 3 4 5 6
Probability 0.1 0.4 0.3 0.2