| Week 1. | Measurement and Description - chapters 1 and 2 |
| | The goal this week is to gain an understanding of our data set - what kind of data we are looking at, some descriptive measurse, and a |
| | look at how the data is distributed (shape). |
| 1 | Measurement issues. Data, even numerically coded variables, can be one of 4 levels - |
| | nominal, ordinal, interval, or ratio. It is important to identify which level a variable is, as |
| | this impact the kind of analysis we can do with the data. For example, descriptive statistics |
| | such as means can only be done on interval or ratio level data. |
| | Please list under each label, the variables in our data set that belong in each group. |
| | Nominal | Ordinal | Interval | Ratio |
| b. | For each variable that you did not call ratio, why did you make that decision? |
| 2 | The first step in analyzing data sets is to find some summary descriptive statistics for key variables. |
| | For salary, compa, age, performance rating, and service; find the mean, standard deviation, and range for 3 groups: overall sample, Females, and Males. |
| | You can use either the Data Analysis Descriptive Statistics tool or the Fx =average and =stdev functions. |
| | (the range must be found using the difference between the =max and =min functions with Fx) functions. |
| | Note: Place data to the right, if you use Descriptive statistics, place that to the right as well. |
| | Some of the values are completed for you - please finish the table. |
| | | | Salary | Compa | Age | Perf. Rat. | Service |
| | Overall | Mean | | | 35.7 | 85.9 | 9.0 |
| | | Standard Deviation | | | 8.2513 | 11.4147 | 5.7177 | Note - data is a sample from the larger company population |
| | | Range | | | 30 | 45 | 21 |
| | Female | Mean | | | 32.5 | 84.2 | 7.9 |
| | | Standard Deviation | | | 6.9 | 13.6 | 4.9 |
| | | Range | | | 26.0 | 45.0 | 18.0 |
| | Male | Mean | | | 38.9 | 87.6 | 10.0 |
| | | Standard Deviation | | | 8.4 | 8.7 | 6.4 |
| | | Range | | | 28.0 | 30.0 | 21.0 |
| 3 | What is the probability for a: | | | | | | | Probability |
| | a. Randomly selected person being a male in grade E? |
| | b. Randomly selected male being in grade E? |
| | | Note part b is the same as given a male, what is probabilty of being in grade E? |
| | c. Why are the results different? |
| 4 | A key issue in comparing data sets is to see if they are distributed/shaped the same. We can do this by looking at some measures of where |
| | some selected values are within each data set - that is how many values are above and below a comparable value. |
| | For each group (overall, females, and males) find: | | | | | | | | Overall | Female | Male |
| A | The value that cuts off the top 1/3 salary value in each group | | | | | | | | | | | "=large" function |
| i | The z score for this value within each group? | | | | | | | | | | | Excel's standize function |
| ii | The normal curve probability of exceeding this score: | | | | | | | | | | | 1-normsdist function |
| iii | What is the empirical probability of being at or exceeding this salary value? |
| B | The value that cuts off the top 1/3 compa value in each group. |
| i | The z score for this value within each group? |
| ii | The normal curve probability of exceeding this score: |
| iii | What is the empirical probability of being at or exceeding this compa value? |
| C | How do you interpret the relationship between the data sets? What do they mean about our equal pay for equal work question? |
| 5. | What conclusions can you make about the issue of male and female pay equality? Are all of the results consistent? |
| | What is the difference between the sal and compa measures of pay? |
| | Conclusions from looking at salary results: |
| | Conclusions from looking at compa results: |
| | Do both salary measures show the same results? |
| | Can we make any conclusions about equal pay for equal work yet? |