30. The following table lists the market share of the four firms in a particular industry in 2010 and total sales for each firm in 2011.

Firm Market Share in 2010 Total Sales in 2011

(in billions of $)

1 0.40 200 2 0.30 180 3 0.20 100 4 0.10 70

a. Specify the competing hypotheses to test w hether the market shares in 2010 are not valid in 2011.

b. Calculate the value o f the test statistic.

c. At the 1% significance level, w hat is the critical value?

d. Do the sample data suggest th at the market shares changed from 2010 to 2011?