HP 33s hp 33s_user's manual_English_E_HDPM20PIE56.pdf - Page 148

Statistical Calculations Once you have entered your data, you can use the functions in the statistics menus. Statistics Menus Menu L.R. x ,y s,σ SUMS Key | | | | Description The linear-regression menu: linear estimation and curve-fitting {T} {P} {E}. See ''Linear Regression'' later in this chapter. The mean menu See "Mean" below. The standard-deviation menu: {Uº} {U See "Sample Standard Deviation" and "Population Standard Deviation" later in this chapter. The summation menu: {Q See "Summation Statistics" later in this chapter. Mean Mean is the arithmetic average of a group of numbers. „ Press | { º } for the mean of the x-values. „ Press | { ¸ } for the mean of the y-values. „ Press for the weighted mean of the x-values using the y-values as weights or frequencies. The weights can be integers or non-integers. Example: Mean (One Variable). Production supervisor May Kitt wants to determine the average time that a certain process takes. She randomly picks six people, observes each one as he or she carries out the process, and records the time required (in minutes): 11-4 Statistical Operations