# Struggling to Run a One Sample t-Test in Excel?

## QI Macros can run a t-test for you in seconds!

Run a
one-sample t-test
using
QI Macros

- Select your data.
- Click on QI Macros menu > Statistical Tools > F & t Tests > One-Sample t-Test
- QI Macros will do the math and analysis for you.

**What is a One Sample t test?**

A one sample t-Test compares test data to a specific value. It helps determine if the sample is greater than, less than or equal to the value.

**Note: ** Excel does NOT do one-sample t-tests; QI Macros adds this functionality.

### One Sample t-Test Example Using QI Macros

Let's say you want to know if the life of a light bulb is greater than 2,500 hours. Take your sample and input the data in Excel.

- Click and drag over the data to select it.

- Next, click on the QI Macros Menu > Statistical Tools > F & t Tests, and then select "t-Test: one sample":
- QI Macros will prompt for a confidence level (default = 0.95)

and a Test Mean (light bulb life is less than or equal to 2,500 hours)

QI Macros will perform the calculations and interpret the results for you:

In this example, p-value = 0.00016 and alpha = 0.05 (1 - .95 the confidence level). Since p < .05 we "Reject the Null Hypothesis (Means are Different)." You can also change the test mean and the calculations with change.

### One Sample Variance Test

To test the variance, put the standard deviation (Stdev) test value in cell E6. The p-value will calculate in F6.

*Note: TInv means "T Inverse" and is used in calculating the upper and lower confidence intervals.*

### What's Cool about QI Macros Statistical Add-in for Excel?

**Interprets the Results for You:** QI Macros compares the p value to alpha and tells you what that means. In the above example, QI Macros tells you to "Reject the Null Hypothesis," because p < 0.05 (Means are Different).

**Interactive Results**: QI Macros lets you change the confidence level and test mean to see what impact those changes have on your results. See cells shaded yellow that can be changed.

### Another t-Test One Sample Example Using Bank Wait Times

Let's say you want to know if wait times in a branch bank are not greater than three minutes at a 95% confidence level.

- H0 <= 3 minutes
- Ha > 3 minutes

Mystery shoppers routinely visit the branch and collect their wait time. This gives us the data we need to test the hypothesis.

- Select your data and then click on QI Macros Menu > Statistical Tools > F & t Tests, and then select "t-Test: one sample."
- Answer the prompts: Confidence level .95 and test mean 3.

The one-sided p value < a (.039776 is less than 0.05 (1-0.95)), so we must "Reject the Null Hypothesis" that bank wait times are less than or equal to 3 minutes.

We can say that we are 95% confident that wait times are greater than 3 minutes.