Question

Based on sales over a six-month period, the five top-selling compact cars are Chevy Cruze, Ford Focus, Hyundai Elantra, Honda Civic, and Toyota Corolla.† Based on total sales, the market shares for these five compact cars were Chevy Cruze 24%, Ford Focus 21%, Hyundai Elantra 20%, Honda Civic 18%, and Toyota Corolla 17%. Suppose a sample of 400 compact car sales in one city showed the following number of vehicles sold.

Chevy Cruze	109
Ford Focus	92
Hyundai Elantra	65
Honda Civic	81
Toyota Corolla	53

Find the value of the test statistic. (Round your answer to three decimal places.)

_____

Find the p-value. (Round your answer to four decimal places.)

p-value =___

Answer 1

use formula E[x] = total cars (n) * proportion (p) for expected value

Category	Observed	Expected
Chevy Cruze	109	0.24*400 = 96
Ford Focus	92	0.24*400 = 84
Hyundai Elantra	65	0.2*400 = 80
Honda Civic	81	0.18*400 = 72
Toyota Corolla	53	0.17*400 = 68
total	400

degree of freedom = number of categories -1 = 5-1 = 4

use TI 84 calculator

Enter Observed values in L1 and expected values in L2 [STAT --> EDIT --> Lists ]

To find test statistic, STAT --> TESTS -->

Observed : [A]

Expected : [B]

df = 4

Press Calculate

Result is = 9.769

p value = 0.0445