In: Statistics and Probability
A restaurant has dishes A, B, C, D, E, F and G
The owners anticipate that dishes will be ordered in the following proportions: 30% (A), 15% (B), 20% (C), 5% (D), 8% (E), 12% (F) and 10% (G). The number of orders placed during the first two days of business was 75 (A), 60 (B), 50 (C), 14 (D), 20 (E), 40 (F), and 41 (G).
State and conduct the appropriate hypothesis test to determine whether there is sufficient evidence at the .05 significance level to conclude the owners’ anticipation is incorrect. What is the p-value associated with the test statistic? (Place bounds on the p-value if necessary.)
Null hypothesis:Ho: owners’ anticipation is correct about proportions of order of dishes
Alternate hypothesis:Ha: owners’ anticipation is incorrect about proportions of order of dishes
degree of freedom =categories-1= | 6 |
for 0.05 level and 6 degree of freedom :rejection region = | 12.592 |
applying chi square test of goodness of fit test:
relative | observed | Expected | residual | Chi square | |
category | frequency | Oi | Ei=total*p | R2i=(Oi-Ei)/√Ei | R2i=(Oi-Ei)2/Ei |
A | 0.300 | 75 | 90.00 | -1.58 | 2.500 |
B | 0.150 | 60 | 45.00 | 2.24 | 5.000 |
C | 0.200 | 50 | 60.00 | -1.29 | 1.667 |
D | 0.050 | 14 | 15.00 | -0.26 | 0.067 |
E | 0.080 | 20 | 24.00 | -0.82 | 0.667 |
F | 0.120 | 40 | 36.00 | 0.67 | 0.444 |
G | 0.100 | 41 | 30.00 | 2.01 | 4.033 |
total | 1.000 | 300 | 300 | 14.378 |
as test statistic X2 =14.378 is higher than critical value we reject null hypothesis and conclude that owners’ anticipation is incorrect about proportions of order of dishes
bound of p values 0.025 < p value <0.05