Sbt2304:Biostatistics Question Paper
Sbt2304:Biostatistics
Course:Bachelor Of Crop Protection
Institution: Meru University Of Science And Technology question papers
Exam Year:2013
QUESTION ONE – (30 MARKS)
(a) The following data was collected from certain test 178 114 110 161 164 155 175 157 108 128 62 30 165 195 87 71 133 151 94 42 141 104 130 167 116 164 156 124 146 149 148 204 140 187 40 197 144 184 87 122 (i) Classify the data using class 30 – 59, 60 – 89, etc. (2 Marks) (ii) Calculate the mean of the data using the classified data. (3 Marks) (iii)Calculate the mode of the data from the classified data. (3 Marks) (iv) Calculate the median of the data using the classified data. (3 Marks) (v) Calculate the standard deviation of the data. (3 Marks)
(b) The following sample was selected from a population that is normally distributed 91 80 99 110 95 106 78 121 106 100 97 82 100 83 115 104 114 118 96 101 79 101 79 130 94 101 Construct a 98% confidence interval for the mean of this data. (4 Marks)
(c) 2 out of 10 dissecting boards are defective. If a technician observe a sample of 3 dissecting boards, determine the probability that (i) At least 2 are defective (2 Marks)
2
(ii) At most 2 are defective (2 Marks)
(d) Calculate the Karl Person’s correlation Coefficient of the data below
X 78 36 98 25 75 82 90 62 65 39 Y 84 51 91 60 68 62 86 58 53 47
(e) Differentiate between type I error and type II error in hypothesis testing. (2 Marks) (f) Differentiate between parametric and non-parametric statistics. (2 Marks)
QUESTION TWO – (20 MARKS)
(a) The probability that a man aged 60 will live up to 70 years old is 0.65. What is the probability that out of 4 men aged 60 years now, 3 of them will live to be 70 years old? (4 Marks0 (b) In a population of 1000 cases, the mean of a certain test is 14 and the standard deviation is 2.5. Assuming the distribution to be normally distributed, find how many cases lie: (i) Between 12 and 15. (2 Marks) (ii) Have 16 (2 Marks) (iii) Below 11 (2 Marks) (iv) Above 17 (v) Between 15.5 and 17.5 (2 Marks) (c) Construct a 95% confidence interval for the mean height of a certain crop on a sample of size 36 with a sample mean of 66 and a standard deviation of 3. (3 Marks)
QUESTION THREE – (20 MARKS)
(a) A certain study was conducted to investigate the risk factor for heart disease among patients suffering from diabetes. In the study, we wish to compare the equality of BMI for male and female patients. A random sample is selected from each population. The sample size for diabetic males was 207 with a mean BMI of 26. 4Kg/m2 and a standard deviation of 3.3Kg/m2. The sample size for diabetic females was 127 with a mean BMI of 25.4Kg/m2 and a standard deviation of 5.2Kg/m2. Investigate at 5% level of significance if the two BMI differ for diabetic males and females in the study. (12 Marks) (b) Perform an analysis of variance (ANOVA) calculation for the data below at ?= 0.05 level of significance.
Factor levels A B C 25 30 40 25 40 50 50 60 80 (8 Marks)
3
QUESTION FOUR – (20 MARKS)
(a) Find the Karl Pearson correlation coefficient between x and y given that: X 129 149 199 99 245 69 99 43 21 57 34 Y 139 155 189 189 259 75 99 78 64 92 56 (7 Marks) (b) Suppose the following set of data is obtained on price for the same 15 pesticides at two competing outlets x and y are as follows. X 319 53 159 179 129 209 149 159 149 112 99 69 245 99 199 Y 339 59 149 189 139 239 115 175 145 109 99 75 259 89 189
Based on this data, test at 5% level of significance if outlet x is cheaper than y using the sign test method. (7 Marks) (c) In investigating the effect of carbon monoxide exposure, an individual with coronary heart disease, forced exhalation volume (FEV) measurements were taken on all patients. This FEV measurements were taken in different hospitals. The sample sizes, sample means and standard deviations in each hospital were computed as follows:
Hospital A B C Sample size 36 41 56 Mean 2.63 3.03 2.88 Standard deviation 0.496 0.523 0.498
Investigate whether the three population means for FEV measurements are equal at ?= 0.05 significance level using ANOVA. (6 Marks)
More Question Papers