Question

The mean high temperature on the equatorial island of Pacifica is µ = 82 F. For a random sample of 30 days following the eruption of a volcano on another island the mean high temperature on Pacifica was 76 F with standard deviation 8 . Does the data indicate that the mean temperature on Pacifica has changed? Use a 5% significance level.

Answer 1

Null hypothesis H₀ :

Alternative hypothesis : H₁

Using Minitab:

Click Stat > Basic Statistics > 1-Sample t... on the top menu, as shown below:

You will be presented with the following 1-Sample t (Test and Confidence Interval) dialogue box:

Click on summerized data and fill required field.

By default, Minitab uses 95% confidence intervals, which equates to declaring statistical significance at the p < .05 level. If you want to change this, you can do so by first clicking on the button, which opens the 1-Sample t - Options dialogue box, as shown below:

Click O. Output of the one-sample t-test in Minitab

P-value < 0.05 we reject the null hypothesis and we conclude that  data indicate that the mean temperature on Pacifica has changed.

Hope this will be helpful. Thanks and God Bless You :)