The file http://myweb.liu.edu/~tbarr/eco72/eco72-lab3-data.xls contains data from the world bank on a few variables from 1999.  The variables are as follows:

Column B:    GDP Growth in 1999
Column C:    Population growth in 1999
Column D:    HIV Prevalence in Women Ages 15-22.

The data have been prepared for you in the file above; alternatively, you can try extracting them yourself from the world bank data site.

Before you begin: Notice that the missing observations in this dataset consist of two dots ("..") instead of blank cells. This is perfectly common; missing data can be coded many ways. You will have to use Excel's search and replace function to replace the two dots with a blank cell.

Step One: Calculate Sample Means and Standard Errors for the Variables

In Cells B212-D212, calculate the sample means for the variables using the =AVERAGE() function.

In Cells B213-D213, calculate the standard error for the variable in the column above the corresponding cell. For example, for Column B, use the formula =STDEV(B2:B209)/SQRT(COUNT(B2:B209)). Use analogous formulas for Columns C and D.

Turn this set of cells into a table by adding column labels for the variables and row labels for the statistics, just as you did for the first two labs.

Step Two: z Statistics for a Couple of Hypotheses

Now, construct z statistics for the following hypotheses:

(i)    The average GDP growth rate is 3 percent.
(ii)    The average population growth rate is 1 percent.
(iii)    The average rate of HIV prevalence among women aged 15-22 is 4 percent.

Put these statistics in Row 214, and label the row. Hint: It is impossible to use too many parentheses in Excel. It is possible to use too few. The answer in Cell B214 should be something close to 0.18.

Step three: Accept or Reject

In Row 215, state whether you accept or reject the hypotheses based on the statistics above, tell me why, and label the row. Use the 5% significance level.

What to Hand In

Be sure to hand in both the output and the formulas. Remember, you can get to the formula view and back by typing CTRL-`. (The "`" key is in the upper-left corner of the keyboard.) Please staple your sheets together. You only need to hand in the table, not the entire spreadsheet.