MA145-B Assignment 1 Hints and Sample Worksheet

If you are new to spreadsheets, here is an example to help get you started.

The sample spreadsheet is called Example4.xls.

You should be able to download it using the above link.

Example4.xls contains the data from Example 4 of Section 2.1, which deals with educational attainment. It is very similar to the assigned problems.

Spreadsheets behave like rectangular arrays of cells. Each cell is identified by its row and column. In the sample spreadsheet, the count of individuals with a high school diploma in 1990 is 47,642,763 and is in cell B5 (Column B, Row 5). Columns are labeled at the top with letters. Rows are labeled at the left with numbers.

You can enter a numbers or words in any cell by moving the cursor to that cell and typing in what you want.

In this exercise, like many of the assigned ones, assume you are given a table of frequencies and asked to produce a chart of relative frequencies.

The first step is to type the data into a frequency table, which occupies columns A through C and rows 2 through 10. The actual data is in rows 3 through 9. Row 2 has column labels and row 10 has totals.

Two cells in this table, B10 and C10, are different from the others in that they contain formulas instead of numbers. Cell B10 contains the formula =sum(B3:B9) which tells the program to calculate the number that goes in this cell as the sum of the numbers in B3 through B9 (vertically). This gives the totals for 1990, which we will need to compute the relative frequency table. The formula for cell C10 is =sum(C3:C9), which tells the program to add up the contents of cells C3 through C9. Formulas are one of the most useful features of spreadsheets. If you change the numbers in any of C3 through C9, you will see the total update automatically as soon as you enter the new number.

The next step is to construct the relative frequencies table. The row labels and column headings are just copied from the frequencies table. There is no Totals line in the relative frequencies table, because they would all be 1.

All of the actual numerical relative frequencies are computed with formulas. These appear in cells B16:B22 and C16:C22. The contents of each cell is a formula that tells the program to divide one of the cells in the frequencies table by one of the totals in the frequencies table. So, for example, the relative frequency for "less than 9th grade" is computed using the formula =B3/$B$10 which tells the program to calculate the cell value for this cell by dividing the contents of cell B3 by the contents of cell B10. Cell B3 has the count for less than 9th grade in 1990, and cell B10 has the totals for 1990.

The $ symbol in front of the B and the 10 in the denominator are just there to allow cutting and pasting of formulas. Cell address with $ symbols do not change when you copy and paste them, others generally do change.

Every cell that will contain a relative frequency contains a formula, which saves you from having to figure them out by hand. If you move the cursor to one of these cells, the formula in the cell will appear at the top under the toolbars.

Once you have the relative frequencies in two columns next to the row labels, you can use the "insert" pulldown menu to insert a chart. With a bit of trial and error, you can get the chart to look the way you want. When you are asked where the data is for the chart, highlight the block of cells in columns A, B, and C and rows 16-22. If you do this, the program will recognize the non-numeric row labels as labels.

Spreadsheets are fairly intuitive and very useful once you get a few of the basic ideas down.