In 2010 a sample of 50 cars was taken, yielding 8 small cars, 27 medium cars and 15 large cars. A sample of 50 cars taken in 2015 revealed 10 small cars, 25 medium cars and 15 large cars. Calculate the chi-squared test statistic here.

Answer 1

Use the Chi-square (X^2) method.

X^2 = ∑ (O-E)^2/E, where O = observed frequency and E = expected frequency.

∑ = sum of all the cells.

E = (column total * row total)/grand total

df = n - 1, where n = number of cells

Look up value in X^2 table in the back of your textbook.