1. Store in column(s): C1-C60
Mean = 80
Standard deviation = 8
Generate 30 rows of data
Store in column(s): C1-C60
Click Calc
Click Random Data
Click Normal
Click OK
Minitab Random Data

2. Chart 9-4: Minitab Confidence Interval Estimates
Confidence level = 0.95
Sigma = 8
Variables = C1-C60
In column C1-C60, we already have the sample data.
Click OK
Click on Stat
Click on Basic Statistics
Click on 1-Sample Z
Chart 9-4: Minitab Confidence Interval Estimates

3. Chart 9-6: Excel Finding Area under a T-Curve
Click on Megastat
Click on Probability
Click on Continuous Probability Distributions
Click OK
Enter degree of freedom (= 10 in our example)
Select “Calculate probability given t”
Enter value of t (= 2.4 in our case)
Select t-distribution
Chart 9-6: Excel Finding Area under a T-Curve

4. Chart 9-7: Minitab Finding Area under a T-Curve
Enter degrees of freedom (in our example, 10)
Optional storage = C2
Input column = C1
Click OK
Select Cumulative Probability
Click on Calc
In column C1, input the value of t (in our example, t = 2.4)
Click on Probability Distributions
Click on t
Chart 9-7: Minitab Finding Area under a T-Curve

5. Chart 9-8: Excel Obtaining a Confidence Interval
Select Descriptive Statistics
Select Confidence Level for Mean and input desired level of confidence (95 in our case)
Select the range of sample data in Column A as the Input Range
Select Summary statistics
Input sample data in Column A
Click OK
Click on Tools
Click on Data Analysis
Click OK
Chart 9-8: Excel Obtaining a Confidence Interval

6. Chart 9-9: Minitab Obtaining a Confidence Interval
Enter Confidence level = 0.95
Enter Variables = C1
In column C1, input the sample data
Click on 1-Sample t
Click on Basic Statistics
Click on Stat
Click OK
Chart 9-9: Minitab Obtaining a Confidence Interval

7. Chart 9-10: Excel Confidence Interval Estimates
Input n = the sample size (= 20)
Input confidence level = 0.95
Click on Confidence interval - p
Input p = the value from step 1 (in our case is 0.55)
Click OK
Input the 0/1 data in column A and find the sample mean x, which is same as sample proportion, p.
Click on Confidence Intervals / Sample Size
Click on MegaStat
Chart 9-10: Excel Confidence Interval Estimates

8. Chart 9-11: Minitab Confidence Interval Estimates
Click Options
Select Use text and interval based on normal distributions
Enter Confidence level = 95.0
Enter Sample in columns C1
Click OK
Click Basic Statistics
Click Stat
Click 1 Proportion
Click OK
Chart 9-11: Minitab Confidence Interval Estimates