ISP 120 Midterm Practice
WARNING: It would be unwise to use this practice as the only studying you do for the midterm. There will additional material on the midterm that is not represented here. Make sure you look over all of the activities and homework.
Percentages
1. Items at a store were marked down 20%. The store then advertises that they will take an additional 20% off at the register when you make your purchase. By how many percent are prices reduced under this sale? The answer is not 40%.
2. Chlorofluorocarbons (CFC's) are chemicals that harm the ozone layer that protects the earth from ultraviolet radiation from the sun; they also cause global warming. CFC's were used in refrigerators (freon is a CFC) and in the making of other chemicals. In 1950, world CFC production was 42 thousand tons. In 1988 their production peaked at 1260 thousand tons. The most recent figures available (1996) put production at 141 thousand tons.
a. By how many percent did production increase from 1950 to 1988?
b. By what factor was the 1996 production larger than the production in 1950?
c. By how many percent was 1996 production less than the production in 1988?
Sorting Data using Excel; Estimation
3. Open the file mileage.xls which contains the city and highway mileage for 1996 model cars and four-wheel drive vehicles. Using Excel's sort function, analyze this data: What are the top three mid-size cars which get the best city mileage? the best highway mileage? Which top 3 4WD vehicles get the best city mileage? the best highway mileage?
4. Estimate how much you'd spend on regular unleaded gas making the 1500 mile road trip from Chicago to the Grand Canyon in a 1996 Toyota Landcruiser. What would you spend on gas if you drove a Jeep Cherokee instead?
Percentages, Percent Change, Rates & Ratios
5. Open the file AccidentalDeaths.xls which lists the number of different types of accidental deaths reported in 1980 and in 1994 for the total population of the United States (U.S. Census Bureau data).
a. What type of accident accounted for the highest number of accidents in both 1980 and 1994?
b. In column D, calculate the percent change for each accident category between 1980 and 1994. [Note: column D may already be formatted to %, which means you do not need to multiply by 100 in your formula]
c. What type of accidental deaths decreased the most during this 14 year time span? What category had the largest increase? What is the percentage change in the number of deaths due to motor vehicle accidents during this time? How does this compare with other types of accidental deaths (meaning, is it higher or lower than most others, or about average)?
d. What was the total number of accidental deaths reported in 1980? in 1994? What percentage of the total accidental deaths are due to motor vehicle accidents in 1980? In 1994? (Hint: use the sum function to total the 1980 accidents and the 1990 accidents in the last cell of each column. Then divide motor vehicle accidents by those totals in each year)
e. Given that the total population of the US in 1980 was 227,726,000, what was the rate of total accidental deaths per 100,000 people in 1980? What would that accidental rate per 100,000 people be in 1994, when the total US population was 260,660,000? (Hint: you do not need to use Excel to do this; you can use a calculator.)
Consumer Price Index; Graphing
For these problems, you'll need to use the file CPI.xls. You might also want to consult the CPI tutorial.
6. In 1965, the new Ford Mustang convertible had a sticker price of $5,000. What would that sticker price be in 1998 dollars?
7. Open the file CarSales.xls, which lists the total revenue in millions of dollars for General Motors and Ford for 1987 to 1996.
a. Which company seems to have done better financially during this time period? Briefly state your position in a paragraph and justify it using the data in the table.
b. Make an XY scatterplot of the Ford revenue from 1987 to 1996. Briefly describe the graph.
c. Convert the series of Ford's revenue to constant 1998 dollars, using the CPI table (Hint: from the CPI table, copy the CPI from years 1987 to 1996 and paste this into the column next to the Ford data. Then use a formula with cell references to convert the Ford data in the first year; drag this formula down the column. Remember to use 1998 CPI in your conversion ratio, not 1996 CPI).
d. Make an XY scatterplot of the resulting adjusted Ford revenue dollars. Briefly describe the graph. Does it differ substantially from the graph in 5a? What can you say about Ford's revenue in this time period?