HP 48gII hp 48gII_user's manual_English_E_HDPMSG48E67_V2.pdf - Page 578

• Obtain single-variable information using: ,Ù @@@OK@@@. Use Sample for the Type of data set, and select all options as results. The results for this example were: Mean: 51.0406, Std Dev: .29.5893..., Variance: 875.529... Total: 10208.12, Maximum: 99.35, Minimum: 0.13 This information indicates that our data ranges from values close to zero to values close to 100. Working with whole numbers, we can select the range of variation of the data as (0,100). To produce a frequency distribution we will use the interval (10,90) dividing it into 8 bins of width 10 each. • Select the program 2. Frequencies.. by using ,Ù˜ @@@OK@@@. The data is already loaded in ΣDAT, and the option Col should hold the value 1 since we have only one column in ΣDAT. • Change X-Min to 10, Bin Count to 8, and Bin Width to 10, then press @@@OK@@@. Using the RPN mode, the results are shown in the stack as a column vector in stack level 2, and a row vector of two components in stack level 1. The vector in stack level 1 is the number of outliers outside of the interval where the frequency count was performed. For this case, I get the values [ 25. 22.] indicating that there are, in my ΣDAT vector, 25 values smaller than 10 and 22 larger than 90. • Press ƒ to drop the vector of outliers from the stack. The remaining result is the frequency count of data. This can be translated into a table as shown below. This table was prepared from the information we provided to generate the frequency distribution, although the only column returned by the calculator is the Frequency column (fi). The class numbers, and class boundaries are easy to calculate for uniform-size classes (or bins), and the class mark is just the average of the class boundaries for each class. Finally, the cumulative frequency is obtained by adding to each value in the last column, except the first, the frequency in the next row, and replacing the result in the last column Page 18-7