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6.49 Shipping holiday gifts: A December 2010 survey asked 500 randomly samples Los Angeles residents which shipping carrier they prefer to use for shipping holiday gifts. The table below show the distribution of responses by age group. The number in parentheses denotes the expected count for that cell.

	18-34	35-54	55+	Total
USPS	72 (81)	97 (102)	76 (62)	245
UPS	52 (53)	76 (68)	34 (41)	162
FedEx	31 (21)	24 (27)	9 (16)	64
Something Else	7 (5)	6 (7)	3 (4)	16
Not Sure	3 (5)	6 (5)	4 (3)	13
Total	165	209	126	500

a) What type of test is appropriate for evaluating if there is an association between age grouping and preferred shipping carrier?

ANOVA
Chi-squared goodness of fit test
Chi-squared test for independence
t-test

b) Write the hypotheses for the test you identified in part a)

H_o: Χ² = 0
H_a: Χ² ≠ 0
H_o: Age and preferred shipping carrier are independent
H_a: Age and preferred shipping carrier are associated
H_o: Age and preferred shipping carrier are associated
H_a: Age and preferred shipping carrier are independent
H_o: μ = 0
H_a: μ ≠ 0

c) Are the conditions for inference using the test you identified in part a) satisfied?

No, some expected counts are below 5
Yes, no expected count exceeds 50% of the sample size
Yes, the sum of the expected counts equals the total sample size
No, the distribution is not uniform

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