In 2008, the New Zealand Planning Institute conducted a postal survey of its members. 341 responses were received. Some of the questions with the number of responses to each answer are given below:
Question 1: How many years have you been working in planning?
Female Male Total
5 or less 52 36 88
6 to 10 53 38 91
11 to 20 44 45 89
21 or more 16 57 73
Total 165 176 341
Question 2: Do you supervise any staff?
Female: Yes (44) Total (165)
Male: Yes (72) Total (176)
Question 3: For each of the following, does
Your organisation contribute to costs?
Professional subscriptions:
Female: Yes (137) Total (165)
Male: Yes (153) Total (176)
Education (texts/training):
Female: Yes (89) Total (165)
Male: Yes (91) Total (176)
Attending conferences:
Female: Yes (114) Total (165)
Male: Yes (129) Total (176)
(a) State the sampling situation for calculating the standard error of the difference in:
(I) estimating the difference between the proportion of female planners who have been working in planning for 6 to 10 years and the proportion of female planners who have been working in planning for 11 to 20 years.
(ii) estimating the difference between the proportion of female planners whose organization contributes to costs for professional subscriptions and the proportion of female planners whose organisation contributes to costs for attending conferences.
(iii) estimating the difference between the proportion of male planners who supervise staff and the proportion of male planners who have worked 11 or more years.
(b) Calculate a 95% confidence interval for the difference between the proportion of female planners whose organisation contributes to costs for attending conferences and the proportion of male planners whose organisation contributes to costs for attending conferences. Interpret your results.
