Drop In Your Data, Get Your Stats
Enter a data set, get the core descriptive statistics back ā basically what you'd get from a TI-84's STAT ā CALC ā 1-Var Stats, minus manually keying numbers into a physical device. Good for homework, lab reports, or double-checking hand-calculated summary stats.
What Gets Calculated
- Mean: the average of your data set.
- Median and mode: where the data set has a clear one.
- Standard deviation: both sample and population.
- Variance: standard deviation, squared.
- Sum and count (n): the raw totals behind the averages.
- Five-number summary: min, max, and quartiles for a box plot.
Sample vs. Population Standard Deviation
This is the detail that trips people up most. Sample standard deviation (Sx on a TI-84, denominator of n ā 1) is different from population standard deviation (Ļx, denominator of n). If your data represents everything you care about, use Ļx. If it's a sample standing in for a bigger population, use Sx.
Using It
- Enter your data values, separated as the tool asks (commas or line breaks).
- Hit calculate.
- Pull whatever specific value your assignment's asking for.
Worked Example: A Small Data Set
Take the data set 4, 8, 6, 5, 3. The mean is (4 + 8 + 6 + 5 + 3) / 5 = 26 / 5 = 5.2. The deviations from the mean are ā1.2, 2.8, 0.8, ā0.2, and ā2.2; squaring and summing those gives 14.8.
For sample standard deviation, divide by n ā 1 (which is 4) to get 3.7, then take the square root: Sx ā 1.92. For population standard deviation, you'd divide by n (5) instead, giving a slightly smaller value of about 1.72 ā a good way to see the difference between the two side by side.
Frequently Asked Questions (FAQ)
Both sample and population standard deviation?
Yes, both Sx and Ļx, so you can use whichever fits your data.
Repeated values or frequencies okay?
Yes, enter them directly and mean/median/everything else accounts for the repeats automatically.
Quartiles for a box plot?
Yes, a full five-number summary is included.
Is it free?
Yes, no account needed.
How much data can I enter?
Whatever's typical for high school or intro college coursework.
Does it calculate mode too?
Yes, alongside mean and median, when there's a clear most-frequent value.
Variance vs. standard deviation ā what's different?
Variance is standard deviation squared. Standard deviation's usually easier to interpret since it's in the same units as your data.
Can I do two-variable/regression data here?
This page is built for one-variable stats. For regression, use the full emulator's STAT menu, which has 2-Var Stats and regression tools.
My standard deviation doesn't match a classmate's on the same data?
Check whether you're both using Sx vs. Ļx ā they give different numbers on identical data.
Sum and count included?
Yes, both show up alongside the rest of the output.