Does the data fit the claim? worksheets

A packet says 1 seed in 5 will fail. You plant 200 and 84 fail. Is the packet wrong, or is that just how seeds go? These free printable worksheets hand over a claim and a result and ask whether the two agree.

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Does the data fit the claim?

The answer key prints on a separate page.

What's on this sheet

Every question here is answered the same way: work out what the claim predicts, then compare. A claim of “1 in k” over n tries predicts n ÷ k, and the numbers are chosen so that division is always whole — a question whose answer depends on how you rounded is not a question worth marking.

Why this sheet works

The three answers are “it fits”, “far too many” and “far too few”, and having to say WHICH WAY is what makes the page work. A student who only judges “that looks wrong” can guess; a student who has to choose between too many and too few has worked the expected count out.

How this one works

Work out what the claim predicts, then compare

expected=n ÷ k

1 in 10 of 400 is 40, and the result was 18

Far too few

A machine is said to make 1 faulty part in 10. In 400 parts 18 were faulty. Before judging the result, work out what the claim says to expect — a claim of "1 in k" over n tries predicts n ÷ k.
1 in 10 of 400 is 40, and the result was 18.
That is about half what the claim predicts, which is too far out to put down to luck.

Reading a studyDoes the result fit the claim?

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