Question

Engineering Statistics. Lab # 2 (chapter 3 Material) Using Minitab to Plot Frequency distribution and calculate Mean, Variance, and Standard Deviation of a general discrete random variable As we discussed in early part of chapter 3 material (Random Variables and Probability distributions), Minitab cannot help you solve general discrete probability problems we have discussed so far, It could be used to graph probability mass distribution and determine mean, Variance, ...of general random variable X when P(x) is given. Suppose you have the following general probability distribution. (note that, this data extracted from a histogram). 5 p(x) 0.25 0.35 0.25 0.10 Procedure: Enter the values of x and p(x) into columns C1 and C2 of a new Minitab worksheet. You can now use the Cale- Calculator command to calculate Mean, Variance, and Standard Deviation, and store the results in columns Cl. C2, and C3 (named "Mean", "variance", and "Std Dev" respectively) of the worksheet. Use the same the three parameters. procedure for In the Calculator dialog box, select "Mean" as the column in which to store mean or expected value. In the Expression box, use the function box, the calculator keys, and the variables list on the left to highlight, select, and create the expression for the mean (See Figure 1) SUM (x p(x)') Mean: Minitab will calculate the value of the Expression (which is formula for "Mean") and store the result in C3. The formula for Variance and Standard Deviation are selected in a similar way: Variance: SUM ((x- 'Mean')**2 *p(x)') Std Dev: Sqrt (Variance') The results should be displayed in the session window, as shown below. Data Display Std Dev 1.71099 Variance 2.9275 P(x) 0.25 Mean Row 1 X 1.85 0 0.35 1 2 0.25 3 3 0.15 5 4

Answer 1

al Minitab Untitled File Edit Data Calc Stat Graph Editor Tools Window Help Assistant TOONL -미x ;Session Data Display P(x) Mean Variance Std Dev Row 10 0.25 1.85 2.9275 1.71099 2 1 0.35 E 15 Worksheet 1*** -미x C6 C11 C13 C18 C19 C20 C1 C2 C3 CA C5 C7 CE CS C10 C12 C14 C15 C16 C17 Variance Std Dev pix Mean 18' C 0.2 2.9275 1.71099 1 0.35 n 25 4 0.15 ... 6 7 8 Project Ma... |lx Current Worksheet: Worksheet 1 Editable