t-tests

Comparing a sample mean to a population mean

  • Question: do children in the city of Eau Claire learn to ride a bicycle earlier than the state average?

  • A survey was conducted in the city of Eau Claire and found the following ages of when children first learned to ride a bicycle:

4.6, 7.5, 7.1, 5.5, 8.9, 12.2, 6.5, 6.1, 6.4, 3.7, 6.8, 7.2

  • The average in the state of Wisconsin is 8.1, but the standard deviation is unknown. What is your conclusion at \(\alpha = 0.05\)?

Two-sample, independent t-test

Refer to Student’s t-test.

Do cars made in Asia get significantly better gas mileage than cars made in Europe? Use this dataset to address the question:

## load packages: readr, dplyr

## read data

## filter data

## data profiling and visualizations

## t.test

Address this question for a different pair of car groupings next!