Which number is missing from each of the following sequences:
a) 20, 30,40,…,60
Categories
Value
Category
0
1
5
6
10
18
20
40
41
42
44
45
46
50
51
53
57
60
70
78
80
90
998
Don't know
999
Sysmiss
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.