OCR Further Statistics AS Specimen — Question 7

Exam BoardOCR
ModuleFurther Statistics AS (Further Statistics AS)
SessionSpecimen
TopicChi-squared distribution

7 The discrete random variable \(X\) is equally likely to take values 0,1 and 2 .
\(3 N\) observations of \(X\) are obtained, and the observed frequencies corresponding to \(X = 0 , X = 1\) and \(X = 2\) are given in the following table.
\(x\)012
Observed
frequency
\(N - 1\)\(N - 1\)\(N + 2\)
The test statistic for a chi-squared goodness of fit test for the data is 0.3 . Find the value of \(N\).