Statistics & Probability

SolverCalc · Statistics

Statistics & Data Calculators

Choose a statistics calculator for averages, spread, percentiles, z-scores, weighted grades, or quick summary values from a data set.

These SolverCalc tools help turn raw numbers into useful data summaries. Start with the question you are answering: center, spread, position, weighted result, or standard score.

Choose the statistics task

Mean, Median, Mode Calculator

Find the center and most common value in a data set when you need a quick descriptive summary.

Example input4, 6, 6, 10, 14Mean = 8; median = 6; mode = 6

Use mean for the arithmetic average, median for the middle value, and mode for the value that appears most often.

Standard Deviation Calculator

Measure how far values typically sit from the mean so you can describe the spread of a data set.

Example input2, 4, 4, 4, 5, 5, 7, 9Population standard deviation = 2

Choose population when you have every value in the group. Choose sample when the data represents a larger group.

Weighted Average Calculator

Combine values when each score, category, or item has a different weight.

Example input90 at 40%, 80 at 60%Weighted average = 84

Weights should describe importance or share. If percentages are used, they should usually total 100%.

Percentile Calculator

Find the relative position of a value inside an ordered data set.

Example inputScore 85 in a sorted class listPercentile depends on rank method

Percentile methods vary. Check whether the task asks for nearest-rank, interpolation, or a school-specific rule.

Variance Calculator

Measure squared spread around the mean and choose the sample or population formula.

Example input2, 4, 6Population variance = 8/3; sample variance = 4

Variance is in squared units. Use standard deviation when you need spread in the original units.

Range Calculator

Find the distance between the largest and smallest values in a data set.

Example input2, 5, 9Range = 9 − 2 = 7

A single extreme value can change the range substantially; compare it with other spread measures.

Quartile & IQR Calculator

Locate the lower and upper quartiles and measure the spread of the middle half.

Example input1, 2, 3, 4, 5, 6, 7Q1 = 2; Q3 = 6; IQR = 4

Quartile conventions differ. Check the method required by your course or dataset.

Z-Score Calculator

Convert a raw value into standard deviations above or below the mean.

Example inputx = 72, mean = 60, SD = 8z = 1.5

A positive z-score is above the mean. A negative z-score is below the mean.

Center, spread and position answer different data questions

Statistics tools are easiest to choose when the wording tells you whether the problem asks for a summary value, variability, or location within a distribution.

  • CenterWhat is the typical value?Use mean, median and mode
  • SpreadHow much do values vary?Use standard deviation
  • Weighted resultDo categories count differently?Use weighted average
  • Relative positionWhere does a value stand?Use percentile or z-score

Data checks before trusting a statistic

  • Separate sample and population

    Standard deviation changes depending on whether the list is the complete population or a sample. Use the rule given by your assignment or report.

  • Watch outliers

    The mean can move strongly when one value is unusually high or low. Compare the median when the data is skewed.

  • Confirm weights and units

    Weighted averages only make sense when each value and weight are paired correctly. Percent weights should usually total 100% before interpretation.

Where statistics tools connect to the rest of SolverCalc

Statistics often uses results from percent, number, and grade tools. Use the hub that matches the next operation in the problem.

  • Decimals & Percent

    Use percent tools when statistics results need percentage change, percent of a value, or percentage formatting.

  • Number Theory & Scientific Notation

    Use number tools when the data includes scientific notation, factors, multiples, or whole-number relationships.

  • Grades & Study

    Use study tools when weighted averages, scores, or final grades need to become academic results.