Using the built-in functions of your SHARP calculator, determine:
- Mean or Average, x
- Standard deviation, sx
- Relative standard deviation, RSD = (sx /x)· 100
for the following set of data: 95, 80, 80, 75, 75, 75, 50
| Screen Display | ||
| Put calculator in statistic mode | 0. | |
|---|---|---|
| Input 95 | (95 M+) |
1. |
| Input 80 two times | ![]() (80 M+) |
2. |
(M+) |
3. | |
| Input a number, 75, three times | (75 STO 3 M+) |
4. |
| Input a number, 50, once | (50 M+) |
5. |
| Screen Display | ||
| To display Mean | (RCL 4) |
75.71428571 |
|---|---|---|
| To display Standard Deviation | (RCL 5) |
13.3630621 |
| To display Relative Standard Deviation | (RCL 5 / RCL 4 * 100) |
17.6493273 |
Therefore, for our data, we can write 75.7 ± 13.4 or 75.7 ± 17.6%
Question: “What should I do if I entered (and stored) a wrong data point on my calculator ? I don’t want to re-enter everything!”
Solution (How to correct after realizing one has stored an incorrect value):
(Courtesy of Vicky Tsui, CENV graduate)
- Continue entering the rest of the data points
- After that’s done, scroll up with the “up arrow” on the calculator to find the incorrect data value
- The calculator will scroll through a series of “X=” and the corresponding “N=” entries (i.e. X1=___, N1=___, X2=___, N2=___, etc.)
- The “X=” fields represent the data points entered, while “N=” denotes the frequency of the corresponding data value (X)
(for the purpose of the lab, N would equal 1 (default)…. unless if you want to specify the N number of times that a value is repeated)
- Once the calculator is displaying the incorrect value, “X= ____” , input the desired correction value and press “M+”
to store this number in its place
DONE 😀 (proceed to find the mean, SD, etc.)
To clear data set
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Start over!
