A phone company plans on offering their new smartphone in four colours: white, black, silver and rose gold. They anticipate that 30% of shoppers will prefer white, 35% will prefer black, 20% will prefer silver and 15% will prefer rose gold. They perform market research by asking a random sample of 350 potential customers which colour they prefer. Color White Black Silve Rose Gold
Frequency 99 135 89 27

Can the company conclude that their expected distribution was accurate using a 10% level of significance?

a. Calculate the test statistic.
b. Determine the critical value(s) for the hypothesis test.
c. Conclude whether to reject the null hypothesis or not based on the test