Statdisk Notes for Activity 7

Entering the Data (Question 4)

  1. Label column 1 of the worksheet as "mass"
  2. Enter the masses that you collected in question 4 in that column.

Summarize the Sample (Question 6)

  1. Choose Data / Descriptive Statistics
  2. Click Evaluate

Checking Normality (Question 9)

Generate a graphical summary of the data

  1. Choose Data / Normal Quantile Plot
  2. Click Plot

The only thing you can't tell from that is the question about the probability plot although it might be easier to spot outliers on the probability plot than the histogram (depending on how far out there they are). To generate a probability plot, do the following.

  1. Choose Stat / Basic Statistics / Normality Test (or you can choose Graph / Probability Plot / Single)
  2. Select the mass variable
  3. Click OK

Performing the Hypothesis Test (Questions 17, 20-22)

The easiest way to find the critical values is to go to Table T in your appendix and look up the value(s). If you are using a normal distribution (see question 15), then use the bottom row of the t-table where it says infinity.

  1. Go to Analysis / Hypothesis Testing / Stat / Mean-One Sample
  2. Choose the proper original claim
  3. Change the significance level if it isn't alpha = 0.05
  4. Enter the claimed mean from the null hypothesis (see question 12)
  5. Enter the population standard deviation if you know it. It is okay to leave this blank, in fact you will most of the time since we almost never know the population standard deviation.
  6. Enter the sample size, sample mean, and sample standard deviation that you found in question 6.
  7. Click Evaluate

Changing to a One-Tail Test (Question 28)

  1. Repeat the section above, but change the original claim to be a greater than
  2. Click Evaluate