HP 10bII - Page 89

Example 1. 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
/Xx?/n:
Keys: Display: Description:
0.00 Clears statistical registers.
@00® 1.00 Enters first time.
Ow 2.00 Enters second time.
Go 3.00 Enters third time.
@С©@(®@#© 4.00 Enters fourth time.
@©О@®@%© 5.00 Enters fifth time.
@©@@@@© 6.00 Enters sixth time.
3.50 Calculates the mean.
аа 0.85 Calculates the sample
standard deviation.
Ө 77.13 Displays Zx?.
Gom 6.00 Displays л.
GC 3.59 Calculates the root mean
square,
The
standard
deviations
calculated
by
QE)
an
OE
are the sample
standard
deviations.
ты,
assume
that
the
data
is
a
sampling
of
a
larger,
complete
set
of
data.
If the data constitutes the entire population, the true
population standard deviations can be calculated by
pressing and EDO.
Example
2.
The
coach
has
four
new
players
on
the
team
with
heights
of
193,
182,
177,
and
185
centimeters
and
weights
of
90, 81, 83,
and
77
kilograms.
Find
the
mean
and
population
standard
deviation
of
both
their
heights
and
weights,
then
sum
the
y-data.
7: Statistical Calculations 89