9231 P43 - Jun 2022 - Q2 - 7 marks
6774
A scientist is investigating the size of shells at various beach locations. She selects four beach locations and takes a random sample of shells from each of these beaches. She classifies each shell as large or small. Her results are summarised in the following table.
| Beach location | ||||||
|---|---|---|---|---|---|---|
| A | B | C | D | Total | ||
| Size of shell | Large | 68 | 69 | 96 | 81 | 314 |
| Small | 28 | 55 | 64 | 39 | 186 | |
| Total | 96 | 124 | 160 | 120 | 500 | |
Test, at the 10% significance level, whether the size of shell is independent of the beach location.
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