In: Statistics and Probability
Newspaper | Pamphlet | |||||
X | P(=X=x) | X*P(X) | Y | P(Y=y) | Y*P(Y) | |
4000 | 0.25 | 1000 | 3000 | 0.3 | 900 | |
6000 | 0.5 | 3000 | 7000 | 0.5 | 3500 | |
9000 | 0.25 | 2250 | 8000 | 0.2 | 1600 | |
Total | 1 | 6250 | Total | 1 | 6000 |
1. Construct a decision tree and show which project you would chose by using the expected value method ()?
The expected value =
Here
Expected profit with newspaper = 6250
Expected profit with pamphlet = 6000
There we should invest in newspaper since it is expected to generate higher profit at same cost.
2. Calculate the coefficient of variation of each project, and determine which one should you chose accordingly?
coefficient of variation = SD(x) / E(x) *100%
SD(x) =
Newspaper | |||
X | P(=X=x) | X*P(X) | x^2*P(X) |
4000 | 0.25 | 1000 | 4000000 |
6000 | 0.5 | 3000 | 18000000 |
9000 | 0.25 | 2250 | 20250000 |
Total | 1 | 6250 | 42250000 |
SD(X) = 1785.357
Pamphlet | |||
Y | P(Y=y) | Y*P(Y) | y^2*P(Y) |
3000 | 0.3 | 900 | 2700000 |
7000 | 0.5 | 3500 | 24500000 |
8000 | 0.2 | 1600 | 12800000 |
Total | 1 | 6000 | 40000000 |
SD(Y) = 2000
Coefficient of variance for news paper = 1785.357 / 6250 * 100
Cov (X) = 28.57%
Coefficient of variance for pamphlet= 2000 / 6000 * 100
Cov (Y) = 33.33%
Coeff of variance gives the dispersion of values around the mean. The greater the cov the greater is dispersion meaning less accuracy and vice versa.
So we see that cov (X) < Cov (y), newspaper would be less risky so we would choose newspaper.
3. Use the Z-table, and show the likelihood that Project and Project 2 will yield a net profit between $7000 and $9000.
z-score = (x- )/
Therefore for news paper = (x - 6250) / 1785.357
P(7000 < X < 9000) = P(X < 9000) - P(Z < 7000)
= P(Z < 1.54) - P( Z < 0.42)
= 0.93826 - 0.66279
P(X) = 0.2755
For pamphlet = (x - 6000) / 2000
P(7000 < X < 9000) = P(X < 9000) - P(Z < 7000)
= P(Z < 1.5)) - P( Z < 0.5)
= 0.93319 - 0.69146
P(X) = 0.24173
4. Assume that the first investment project will cost you $2000 less than the second one. Support how that would change your decision, if at all.
First investment is costing less than pamphlet by 2000. So the netprofits of pamphlets will reduce to 4000 due to increase in cost by 2000. This still favors newspaper investment. So we will still be investing in newspaper.