Probability & Statistics
Goodness of Fit Test
Name________________
1. A staff member of an emergency medical service wishes to determine whether the number of accidents is
equally distributed during the week. A week was selected at random, and the following data were obtained.
Is there evidence to reject the hypothesis that the number of accidents is equally distributed throughout
the week, at  = 0.05?
Day
Mon.
# accidents
28
Tues.
32
Wed.
15
Thurs.
14
Fri.
38
Sat.
43
Sun
19
2. The chair of the history department of a college hypothesizes that the final grades are distributed as 40%
A's, 30% B's, 20% C's, 5% D's and 5% F's. At the end of the semester, the following numbers of grades
were earned. For  = 0.05, is the grade distribution for the department different from that expected?
Grade
Number
A
88
B
70
C
44
D
12
F
10
3. The concessions manager at Twin Rivers Stadium wishes to see whether there is any preference in the
flavors of popcorn that are sold during sporting events. A random sample of sales is selected, and the data
are shown below. At  = 0.01, are the flavors selected with equal frequency?
Flavor
# sold
Plain
25
Barbecue
18
Butter
32
Cheddar
45
4. The American Red Cross reports that 42% of Americans have type 0 blood, 44% have type A blood, 10%
have type B blood, and 4% have type AB blood. A county medical examiner hypothesizes the distribution ob
blood types is the same in his county as it is nationally. A random sample of 200 people is selected, and the
following data are tallied. At  = 0.10, can the examiner conclude that his hypothesis is correct?
Type
Frequency
O
58
A
65
B
55
AB
22