Download STA 2023 Handout #2 Statistics Dr. D. P. Story Fall 2006 Below are

STA 2023
Dr. D. P. Story
Handout #2
Statistics
Fall 2006
Below are some notes on the use of the TI-84 calculator. The procedures for computing various sample statistics should be
pretty much the same for all TI calculators. Consult your user manual.
To calculate the mean:
Working with ungrouped data
To Enter data into a list: To make a statistical calculation, you need to enter the data set into the device. The
steps are. . .
1. 9 (Note: y …)
2. Math
3. Í
1. …
4. 3: mean(
2. Edit
5. Í
3. 1:Edit
6. mean( $
4. Í
7. mean(d)
5. Select a list, say d
6. At this point you enter your data, one at a time,
hitting Í to go to the next entry.
The same procedure can be repeated by using the different
functions available through the Math menu of 9
• Median: Use 4: median(, enter median(d)
7. Press 5 to quit the … menu
To Compute sample statistics x̄, s and σ: Assuming
you have already entered your data set into a list, follow
the steps below to compute standard statistics:
• Sample Standard Deviation: Use 7: stdDev(, enter
stdDev(d)
• Sample Variance: Use 8: variance(, enter
variance(d)
1. …
Working with grouped data
2. Calc
3. 1: 1-Var Stats
The same procedures can be performed with grouped data.
4. Í
To Enter data into a list for Grouped Data: To
make a statistical calculation, you need to enter the data
set into the device. Repeat the steps listed above in To
Enter data into a list; enter the midpoints of each class
into one list, and enter the frequency of each class into
another list—of course in the same order.
5. 1-Var Stats $ (Here, $ represents the blinking
cursor.)
6. The blinking cursor indicates the calculator is waiting for input. Enter the name of your list, for example, d
7. Í
8. The output
2 of the 1-Var Stats procedure lists: x̄,
x,
x , sx (the sample standard deviation) and
σx (the population standard deviation).
To Compute sample statistics given n,
x and
x2
1. x̄ = n1
x
2 1 2
2. SSx =
x − n ( x) (The sum of squared deviations)
3. σx2 =
4. s2x =
1
n SSx (population variance)
1
n−1 SSx (sample, or unbiased,
5. σx = σx2
6. sx = s2x
For the purpose of illustration, assume the midpoints are
listed in d and the frequencies are listed in e.
To calculate Grouped mean:
1. 9 (Note: y …)
2. Math
3. Í
4. 3: mean(
5. Í
6. mean( $
7. mean(d,e)
variance)
The same procedure can be repeated by using the different
functions available through the Math menu of 9
• Median: Use 4: median(, enter median(d,e)
To Compute individual statistics using TI functions
• Sample Standard Deviation: Use 7: stdDev(, enter
stdDev(d,e)
For the purpose of illustration, assume the midpoints are
listed in d.
• Sample Variance: Use 8: variance(, enter
variance(d,e)