HP 10bII+ Financial Y7V¡, D7GV¡, D7V¡, D7jV¡, Mean, Standard Deviations, and Summation Statistics

Mean, Standard Deviations, and Summation Statistics

You can calculate the mean (x ), sample standard deviation (Sx), and population standard deviation (σx), and summation statistics, n, Σ x, and Σ x 2of x-data. For x,y data, you can also calculate the mean, sample standard deviation, and population standard deviation of the y- data and the summation statistics Σ y, Σ y 2, and Σ xy.

Example 2

A yacht captain wants to determine how long it takes to change a sail. She randomly chooses six members of her crew, observes them as they carry out the sail change, and records the numbers of minutes required: 4.5, 4, 2, 3.25, 3.5, 3.75. Calculate the mean and sample standard deviation of the times. Also, calculate the root mean square, using the formula,

∑x2 ⁄ n.

Table 12-7 Example calculating mean, standard deviation, and summation statistics

KeysDisplay Description

\t	STAT CLR	Clears statistics memory.
	(message flashes briefly,
	then disappears)
Y7V¡	1.00	Enters first time.
Y¡	2.00	Enters second time.
G¡	3.00	Enters third time.
D7GV¡	4.00	Enters fourth time.
D7V¡	5.00	Enters fifth time.
D7jV¡	6.00	Enters sixth time
\k	3.50	Calculates the mean.
\h	0.85	Calculates the sample standard
		deviation.
]l	77.13	Displays Σx .
		2
a][	6.00	Displays n.
4\B	3.59	Calculates the root mean
		square.

120 Statistical Calculations