Answer:
Pvalue = 0.020335
X² = 14.99
CONCLUSION: THERE IS DIFFERENCE IN MARKET SHARES
Step-by-step explanation:
H0 : there is no difference in market shares
H1: there is difference in market shares
Chisquare (X²) = (observed - Expected)²/ expected
Honda Civic - 0.20 * 400 = 80 : (98-80)^2 /80 = 4.05
Toyota Corolla - 0.17 * 400 = 68 : (72-68)²/68 = 0.235
Nissan Sentra - 0.12 * 400 = 48 : (54-48)²/48 = 0.75
Hyundai Elantra - 0.10 *400 = 40 : (44-40)²/40 = 0.4
Chevrolet Cruze - 0.10 * 400 = 40 : (42-40)²/40 = 0.1
Ford Focus - 0.08 * 400 = 32 : (25-32)²/32 = 1.531
Others - 0.23 * 400 = 92 : (65-92)²/92 = 7.924
X² = (4.05+0.235+0.75+0.4+0.1+1.531+7.924) = 14.99
The obtain the Pvalue ;
We use the Pvalue from Chisquare calculator :
Pvalue(14.99, 0.05, df= 6) = 0.020335
Decision region :
Reject H0 ; if Pvalue < α
THERE IS DIFFERENCE IN MARKET SHARES
Market share differences:
* 98/400 = 0.245,
0.245-0.20 = 0.045
* 72/400 = 0.18,
0.18 - 0.17 = 0.01
* 54/400 = 0.135,
0.135 - 0.12 = 0.015
* 44/400 = 0.11,
0.11 - 0.10 = 0.01
* 42/400 = 0.105
0.105 - 0.10 = 0.005
* 25/400 = 0.0625
0.0625-0.08 = -0.0175
* 65/400 = 0.1625
0.1625 - 0.23 = -0.0675
, it can be expanded as 