ECON 10223 Study Guide - Quiz Guide: Fixed Cost, Tevet

3. A decision at the margin

Van is a hard-working college senior. On Thursday, he decides to work nonstop until he has answered 200 practice problems for his economics course. He starts work at 8:00 AM and uses a table to keep track of his progress throughout the day. He notices that as he gets tired, it takes him longer to solve each problem.

Use the table to answer the following questions.

The marginal, or additional, gain from Van's first hour of work, from 8:00 AM to 9:00 AM, is:

The marginal gain from Van's third hour of work, from 10:00 AM to 11:00 AM, is:

Later, the teaching assistant in Van's economics course gives him some advice. Based on past experience, the teaching assistant says, working on 30 problems raises a student's exam score by about the same amount as reading the textbook for 1 hour. For simplicity, assume students always cover the same number of pages during each hour they spend reading.

Given this information, in order to use his 4 hours of study time to get the best exam score possible, how many hours should he have spent working on problems, and how many should he have spent reading?

1 hour working on problems, 3 hours reading

2 hours working on problems, 2 hours reading

3 hours working on problems, 1 hour reading

4 hours working on problems, 0 hours reading

5. A decision at the margin

Larry is a hard-working college freshman. On Saturday, he decides to work nonstop until he has answered 200 practice problems for his economics course. He starts work at 8:00 AM and uses a table to keep track of his progress throughout the day. He notices that as he gets tired, it takes him longer to solve each problem.

Use the table to answer the following questions.

The marginal, or additional, gain from Larry's second hour of work, from 9:00 AM to 10:00 AM, problems.

The marginal gain from Larry's fourth hour of work, from 11:00 AM to noon, problems.

Later, the teaching assistant in Larry's economics course gives him some advice. Based on experience, the teaching assistant says, working on 70 problems raises a student's exam score by about the same amount as reading the textbook for 1 hour. For simplicity, assume students always cover the same number of pages during each hour they spend reading.

Given this information, to use his 4 hours of study time to get the best exam score possible, how many hours should he have spent working on problems and how many should he have spent reading?

0 hours working on problems, 4 hours reading

1 hour working on problems, 3 hours reading

2 hours working on problems, 2 hours reading

3 hours working on problems, 1-hour reading

Suppose your friend Alex made a New Year's resolution to lose weight and has asked you for help. You begin by tracking his weight over the first seven days in January and record his weight on each day, along with other variables of interest. The data you collect is displayed in the following table. Obsno Date Period Height Weight Calories Sleephrs Gender Weekday (Day) (Inches) (Pounds) 1 1/1 1 66 190 2,200 8 Male Monday 2 1/2 2 66 191 2,200 10 Male Tuesday 3 1/3 3 66 190 2,200 8 Male Wednesday 4 1/4 4 66 191 2,200 3 Male Thursday 5 1/5 5 66 190 2,100 8 Male Friday 6 1/6 6 66 193 3,800 9 Male Saturday 7 1/7 7 66 196 4,000 7 Male Sunday • obsno = Observation number • date = Date data were collected • period = Index equal to 1 on first date, 2 on second date, and so on • height = Height in inches • weight = Weight in pounds • calories = Calories consumed on that date • sleephrs = Hours slept that night • gender = Sex of the individual The data in the table is an example of a data set, with a data frequency. True or False: When performing econometric analysis on this type of data, it is a best practice to sort the data in chronological order. False True Use the data in the table to plot the weight over time (Period, Weight) by dragging the symbol at the right onto the graph. Plot Period on the horizontal axis and Weight on the vertical axis. Weight012345678200198196194192190188186184182180WEIGHT (Pounds)TIME PERIOD (Day) Alex's weight over the weekend. Suppose his weight increases every weekend, due to the drinks and high-calorie foods he consumes at the parties he attends. This periodic increase in weight is an example of .