Question

In which of the following situations would it make the most sense to use a chi-squared goodness-of-fit test? Read carefully!

		A few years after the automobile manufacturer financial bailout, industry analysts were interested in determining if the reliability of cars (as measured by whether a major repair was needed in the preceding 12 months) was associated with the location of the manufacturer (Asia, Europe, or the U. S.). The analysts took a survey of customers nationwide, asking each to record the location of manufacture and whether or not the customer had any problem within the preceding 12 months.
		An industry research group wants to determine if the market share--that is, the proportion of the market's total sales--for the smartphone vendors Samsung, Apple, LG, and others is the same as it was a year ago. The company conducts a survey of 300 randomly selected smartphone users and records the number of users for each vendor.
		An analyst at an investment firm wants to see if the mean value (in dollars) of 401(k) retirement accounts is the same for male and female investors. He takes a random sample of 250 accounts for customers of the same approximate age and notes the gender of the investor and the dollar value of the account.
		An insurance company is investigating the possibility of offering renter's insurance in a particular state. The decision rests on whether the mean dollar amount of a claim is such that the company could offer the policy and make a profit. The company examines a random sample of 600 claims over the past five years across the state, recording the dollar amount of the claim.
		A new account analyst at a bank is interested in determining if the distribution of the ages of customers coming in for service is associated with the location of the bank branch. He gathers data from 400 randomly selected transactions, recording the customer's age category (less than 30, 30-55, 56 and older) and which branch the customer visited (main branch or mall branch).

Answer 1

Option: An industry research group wants to determine if the market share--that is, the proportion of the market's total sales--for the smartphone vendors Samsung, Apple, LG, and others is the same as it was a year ago. The company conducts a survey of 300 randomly selected smartphone users and records the number of users for each vendor.

(Here Null hypothesis, H₀: The proportion of the market's total sales--for the smartphone vendors Samsung, Apple, LG, and others is the same as it was a year ago; Alternative hypothesis, H₁: H₀ is not true)