Last Year, Brand a Mobile Android Phones Had 45% of the Market

question 1

Essay

Last year, Brand A mobile android phones had 45% of the market, Brand B had 35% and Brand C had 20%. This year the makers of Brand C launched a heavy advertising campaign. A random sample of mobile phone stores shows that of the 10,000 android mobile phones sold, 4350 were Brand A, 3450 were Brand B, and 2200 were Brand
C.Has the market changed? Test at $\alpha =$ 0.05.

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Definitions:

Standard Error of the Estimate

A statistical measure that indicates the accuracy with which a sample represents a population.

GPA

Grade Point Average, a standardized measure of academic achievement within a specific period, calculated by dividing the total amount of grade points earned by the total amount of credit hours attempted.

Norm Referencing

A method of scoring in which test scores are compared to a group of other scores called the norm group.

Norm Group

A reference population used to establish benchmarks or standards for comparing and interpreting the scores of individual test-takers.