Search & Filtering
The Dean the School of education, Mount Kenya University wants to determine whether there are statistically significant difference of opinion among the different cadres of academic staff members at the university concerning a proposed curriculum change in which postgraduate students are to be taught research methods on-line. Interviewing a sample of 313 members of the academic staff constituting 104 Lecturers, 131 Senior Lecturers, and 78 Professors, the Dean obtained the results shown in the following table:
Rank
Response
Lecturer
Senior Lecturer
Professor
Total
Against
47
34
14
95
Not committed
41
49
29
119
In support
16
48
35
99
Total
104
131
78
313
Compute a chi-square test for the above data and draw conclusion at α = .05
A large group of students took a test in Physics and the final grades have a mean of 70 and a standard deviation of 10. If we can approximate the distribution of these grades by a normal distribution, what percent of the students
i) scored higher than 80? (3mks)
ii) should pass the test? (3mks)
The following were the scores obtained by Form II students in a Mathematics
49
63
59
58
44
49
51
62
37
30
49
45
52
50
42
54
32
57
41
42
56
44
46
63
44
40
50
46
53
48
37
46
53
68
66
58
36
40
56
37
66
43
40
43
51
59
42
52
46
57
Required
a) Group the data into 7 classes and Make a grouped frequency distribution
(i) Mean mark
(ii) Mode
(iii) Median mark
(iv) 70th percentile mark
(v) Standard deviation
Comment on the distribution of marks
A survey found that one out of four Filipinos says he or she has visited a dentist in any given month. If 12 people are selected at random, find the probability that (a) exactly five have visited the dentist last month.
The ages, x years, of 18 people attending an evening class are summarized by
the following totals:
Σx= 745,Σx^2= 33951
(i) Calculate the mean and standard deviation of the ages of this group of people.
(ii) One person leaves the group and the mean age of the remaining 17 people is
exactly 41 years. Find the age of the person who left and the standard deviation of the ages of the remaining 17 people.
Delip measured the speeds, x km per hour, of 70 cars on a road where the
speed limit is 60 km per hour.
His results are summarized by Σ(x − 60) = 245.
(i) Calculate the mean speed of these 70 cars.
His friend Sachim used values of (x − 50) to calculate the mean.
(ii) Find Σ(x − 50).
(iii) The standard deviation of the speeds is 10.6 km per hour. Calculate
Σ (x- 50)^2
Marks of ten students in Probability are given below
2,3,6,8,11,a,17,20,28,b
If mean of the marks is 1.4 and median is 13. Find the values of a and b.
A computer can generate random numbers which are either 0 or 2. On a particular occasion, it generates a set of numbers which consists of 23 zeros and 17 twos. Find the mean and variance of this set of 40 numbers.
If the teacher decided to pass the upper 50% of the students. What is the passing score?
In a study analyzing the determinants of demand for gasoline in the United States, the results
shown below were obtained. The dependent variable is miles traveled per car per year (K) and
the explanatory variables are C, number of cars (millions); M, miles per gallon; Pg, retail
gasoline price index deflated by consumer price index (1953=100); PT, price of public transport
(1967=100); Pop, population (millions); L, labour force; Y, per capita disposable income in 1958
prices.
a. Do the coefficients have the expected signs? Explain
b. Is there a multicollinearity problem? Use at least four diagnosis procedures to answer this
question. If there is multicollinearity, what might be causing it?
c. If there is multicollinearity problem discuss two remedial measures to remedy the situation
#339914 on Dec 2023