Sma2262:Statistics Question Paper
Sma2262:Statistics
Course:Bachelor Of Science In Food Science And Nutrition
Institution: Meru University Of Science And Technology question papers
Exam Year:2013
QUESTION ONE (30 MARKS)
a) Define the following terms as used in statistics i. Population (1 Mark) ii. Raw data (1 Mark) iii. Null hypothesis (2 Marks) b) i) Briefly outline four principles to be observed when tabulating statistical data. (4 Marks) ii) In January 1995, a firm employed 90 staff whom 79 were men. During the year 17 staff left and 13 of these were men. The total recruitment during the year was 13 out of whom 3 were women. During 1996 wastage declined by 3 amongst men compared with 1995 and no women left. 6 more men but 2 fewer women were recruited than in the previous year. The total number employed on 1st January 1997 amounted to 93. Arrange the information in tabular form showing all relevant totals and sub-totals. (5 Marks) c) A family has six children. Find the probability P that there are i. Three boys and three girls (2 Marks) ii. Fewer boys than girls.
Assume that the probability of any particular child being a boy is ½. (3 Marks)
d) The examination marks obtained by 100 candidates are distributed as shown below. Marks 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 No. of candidates 8 7 14 23 26 12 6 4 From the above distribution calculate:
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i. Mean (2 Marks) ii. Median (3 Marks) iii. Mode (2 Marks) iv. Standard deviation (3 Marks) e) A discrete random variable x follows Poisson Law. Find: > 2 2, if it is given that = 2.5. (2 Marks)
QUESTION TWO (20 MARKS)
a) Define correlation and state the importance of correlation analysis. b) The following table lists average male weight in pounds and height in inches. Weight 20 30 45 60 75 140 155 Height 28 36 44 50 60 66 70 Find the correlation coefficient r for weight and height. Comment on the correlation
QUESTION THREE (20 MARKS)
Consider the following 50 values listed in order, column by column
10 20 35 44 55 64 75 81 87 99
11 22 36 48 56 68 76 82 89 101
13 23 38 49 57 69 76 83 90 102
15 23 41 50 60 70 78 83 94 105
18 30 44 50 63 73 80 85 96 107
a) Find i. P40 ii. P65 iii. P82 b) Find i. First quartile (Q1) ii. Second quartile (Q2) iii. Third quartile(Q3) c) The ages of workers in the Mafuko bakery are normally distributed, with a mean of 45 years and standard deviation of 12 years. A worker is stopped at random and asked to fill out a questionnaire. What is the probability that this worker is i. Less than 30 years old ii. Between 35 years and 55 years old iii. More than 60 years old.
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QUESTION FOUR (20 MARKS)
a) A certain drug is claimed to be effective in during cold. In an experiment on 500 persons with cold, half of them were given the drug and half of them were given sugar pills. The patients’ reactions to the treatment are recorded in the table below.
Helped Harmed No effect Drug 150 30 70 Sugar pills 130 40 80
On the basis of this data, can it be concluded that here is a significant difference in the drug and sugar pills? b) The prices of shares of a company on different days in a month were found to be 66, 65, 69, 70, 69, 71, 70, 63, 64 and 58. Discuss whether at 5% level of significance the mean price of the shares in the month is 65.
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