HP 35s HP 35s scientific calculator - User Guide - Page 169

To correct statistical data: 1. Reenter the incorrect data, but instead of pressing , press  . This deletes the value(s) and decrements n. 2. Enter the correct value(s) using . If the incorrect values were the ones just entered, press   to retrieve them, then press   to delete them. (The incorrect y-value was still in the Y- register, and its x-value was saved in the LAST X register.) After deleting the incorrect statistical data, calculator will display the value of Y-register in line 1 and value of n in line 2. Example: Key in the x, y-values on the left, then make the corrections shown on the right: Initial x, y 20, 4 400, 6 Corrected x, y 20, 5 40, 6 Keys:   () Display: Description: Clears existing statistical data. Enters the first new data pair. Display shows n, the number of data pairs you entered. Brings back last x-value. Last y is still in Y-register. Deletes the last data pair. Reenters the last data pair. Deletes the first data pair. Statistical Operations 12-3