Solvecoon

Statistics solver

Statistics, with
the interpretation.

In statistics the number is half the answer. What it means for the claim being tested is the other half, and it is the half most solvers skip. Solvecoon writes the formula, the substitution, the result, and the sentence that says what it tells you.

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Free to try — 5 solves every day. No credit card.

How it works

1

Snap the data

Tables, output from a stats package, and histograms all read fine as a captured region.

2

See the formula before the number

Which formula, why that one, and what each symbol refers to in your data.

3

Read the conclusion in words

Reject or fail to reject, and what that means about the original claim.

What it handles

Descriptive statistics

Mean, median, mode, range, variance, standard deviation, quartiles, and outliers.

Probability

Independent and dependent events, conditional probability, and tree diagrams.

Counting

Permutations, combinations, and knowing which of the two the question is asking for.

Distributions

Binomial, normal, and z-scores, including reading a table or using the calculator function.

Inference

Confidence intervals, hypothesis tests, p-values, and what significance does not mean.

Regression

Line of best fit, correlation, residuals, and why correlation is not causation.

A real one, worked out

This is the shape of every answer: the result first, then the reasoning that got there.

Question

Find the mean and sample standard deviation of: 4, 8, 6, 5, 3

Answer

Mean = 5.2, sample standard deviation is about 1.92

Steps

  1. 1Add the values: 4 + 8 + 6 + 5 + 3 = 26.
  2. 2Divide by n = 5: mean = 5.2.
  3. 3Deviations from the mean: -1.2, 2.8, 0.8, -0.2, -2.2.
  4. 4Square them: 1.44, 7.84, 0.64, 0.04, 4.84. Sum = 14.8.
  5. 5Sample variance divides by n - 1 = 4: 14.8 / 4 = 3.7.
  6. 6Take the root: standard deviation is about 1.92.

Divide by n - 1 for a sample and by n for a whole population. Reading the question for which one you have is worth more marks than the arithmetic.

Solvecoon raccoon mascot

A p-value is not the probability that you are right. Ask me why.

What it will not do

  • It will not run on your graded stats exam.
  • It will not know whether your data is a sample or a population unless the question says.
  • It will not turn a badly designed study into a valid one. It will tell you the design is the problem.
  • It will not replace your software output. It reads it and explains it.

Solvecoon is a study aid, not an answer machine. Exams, graded quizzes, and proctored tests are off limits — see the acceptable use policy.

Questions people ask

Can it read output from SPSS, R, or Excel?
Snap the output table and it will explain which numbers matter, what the test was, and what the result says about your hypothesis.
Does it explain when to use which test?
Yes, and that is usually the real question. It names the test, states the assumptions the test needs, and checks them against your description of the data.
Sample or population standard deviation?
It uses whichever the question implies and says which one it used. If the wording is ambiguous, it shows both.
Will it interpret a confidence interval correctly?
It states the interval and then the interpretation in plain words, including the common misreading it is not.
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Stuck on something?

Select it or snap it — Solvecoon understands it.

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Free to try — 5 solves every day. No credit card.