Test 2 and Midterm grades

On your test 2 printout there is are two numbers in red. The top number is your adjusted raw score on test one. Recall that I had made two errors on the key and this information is for your updated records.

The second number is your "points to date". It is out of a possible 49 points. (You can take your points, divide by 49 to get your percentage score. Midterm grades can be interpreted from the following distribution of points out of 49:

A: 39.51 and higher
B: 34.30 to 39.50
C: 28.40 to 34.29
D: 22.00 to 28.39
F: below 20

Scores on test 2 out of a possible 40 points:

A: 33.5 and higher
B: 27.5 - 33
C: 22 - 27
D: 16.5 - 21.5
F: 16 and lower

Answer key to sample problems for test 2

Here is the key to the sample test. I will try to be online for a while this evening but I'm not feeling that great so I'm sorry if I don't show up or only on for a short time.

1-B, 2-A, 3-A, 4-D, 5-A, 6-B,
7-D, 8-B, 9-B, 10-B,
11-D, 12-C, 13-C, 14-B, 15-C,
16-B, 17-A, 18-C, 19-A, 20-A, 21-A, 22-D, 23-C,
24-D, 25-A, 26-B, 27-D,
28-C, 29-B, 30-A, 31-C,
32-B, 33-B, 34-C, 34(second one)-E, 35-B, 36-B, 37-C,
38-B, 39-A, 40-A, 41-B, 42-D,
43-C, 44-D, 45-C, 46-C, 47-C, 48-B, 49-C,
50-A, 51-C, 52-B, 53-B, 54-A or D*

*Comment on #54. The demand for milk will certainly increase, driving up the price and quantity. The effect on the supply side could be debatable. In microeconomic analysis of a firm supply of a good, it is discovered that the supply decision is based only on marginal cost. Here you are told there is a costly advertising campaign. Does the cost of an advertising campaign vary with the level of output or is it a "fixed" or "one time" cost? If this is (and arguably could be) more like a fixed cost, the supply decisions would not change (and supply would not move) and the answer would be A. However, if you argue that the supply would decrease then unambiguously price will rise but the combined effect of decrease in supply and increase in demand would leave us uncertain about equilibrium quantity. This is a tough argument and if appeared on a test, I would accept both. But I hope to avoid such unclear problems on a test. (Sorry.)



Here is the answer for the PPF problem:

You can plot the PPF by treating the combinations of Truck and Corn as "ordered pairs" on the diagram.

A. 10 bushels, 15 bushels, 20 bushels, 25 bushels

B. Opportunity cost is increasing.

C. The combination is feasible but inside the limits of the PPF. The economy is not using its resources efficiently or there is some unemployment and other idle resources.

D. The combination is not feasible. It lies outside the PPF. The way to get to that production point is more resources or better technology. (Be careful, you can trade to get a consumption bundle outside of the PPF, however, the question clearly asks if it is a possible production point. Trade does not enter into this answer.)

Let me know if you think any of these answers is incorrect. There could be a typo or I could have just done the problem wrong.

Good luck.

Homework #4

In the instructions it says to read chapter 4. That is a mistake. It should be chapter 3. However, those page numbers for the tables that are referenced are correct.

Comments on Test 1

There will be a few adjustments to your scores on Test 1. It is my fault that I incorrectly coded in two responses on the answer key for the multiple choice problems.

9. Correct answer is B (or "2" on your printout). It was improperly coded as D ("4").
10. Correct answer is D (or "4"). It was improperly coded as C ("3").

I will review the original scan sheets and make the appropriate corrections.

If you correctly answered 9. B and/or 10. D, you will get the point(s) added to your raw score.

Please note: If you answered 9. D and/or 10. C, one (or two) point(s) will be deducted from your raw score. You can be pissed if you want but the important thing to note is that you are not actually getting anything taken away. It was unearned to begin with.

This may alter the curve, but not in a significant manner.

This adjustment will be done automatically and you should be able to make the adjustment on your returned answer sheets. If any more information needs to be reported I will certainly add another note.

I apologize for the inconvenience. But it's better to be right than wrong.

J

Test 1 grade distribution

Ok, so the scores were not ideal, but since I strongly believe that each test has an inherent difficulty bias, it is appropriate that some adjustment or "curve" be in place. Now the following is not an "official curve" since the only curve that matters is the one based on final scores at the end of the semester. However, the following information shows how I go about setting a curve and the grade ranges given are to be used only as a guideline as to the quality of your work.

Ultimately, the curve at the end of the semester will essentially be a weighted average of the curves for the test. Remember, this is only a guideline. I do not record a letter grade (therefore at some future point in the semester, it will be inappropriate to say to me "I got a B on the first test and a C on the second test, will I still be able to get an A?" What matters is how high or low of a score you got in those B or C ranges. I give you the scale so that you can personally assess the quality of your work.

First, some descriptive statistics out of 35 possible points (divide your raw score by 35 and then multiply by 100 to put your score into percentage terms):

average = 21.28 (60.8%)
median = 21.5 (61.4%)
standard deviation = 4.36 (12.5%)

My goal is an average of 80% with a standard deviation of 10%.

I use the average or median (or maybe somewhere between the two) as the lowest "B" and the A-B break approximately one standard deviation above and the C-D break one standard deviation below the mean. The F range would be more than one standard deviation below the mean.

Here is a useful guide for interpretation of your scores (this may vary slightly from the one presented in class, but not by very much):

A range: 26+ (15 observations)
B range: 21.5 - 25 (35 observations)
C range: 17 - 21 (31 observations)
D range: 12.5-16.5 (15 observations)
F range: 12 and lower (1 observation)

I always like it when the sum of the As and Bs is greater than the sum of Cs, Ds, and Fs. I think this is a very fair scale.

If you did not get the score you hoped for, most can do better with the following advice: spend more time with the material. Cram sessions have quick diminishing marginal productivity. You should keep up with the readings. You should actually attempt to do the homework. You should not just read your notes and use a highlighter. Try copying your notes or typing them up. Allocate some time for this activity. I know this class competes with other time. Time is a scarce resource. Allocate wisely.

You will have a second test and I will give you information on a "half term grade" after the second test.