Tiêu đề Probability and statistics Boards Qns.pdf ✅

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Prepared by Uni Bytes / www.unibytes.xyz Don't use our content without permission. Tribhuvan University Faculty of Humanities and Social Science Semester: III Subject: Probability and Statistics 2021 Batch Group B Attempt any SIX questions 2. Discus the role of statistics in computer application. 3. Define Statistics? The following of telephone calls received at an exchange for 200 successive one-minute intervals are given below. No of cells 0 1 2 3 4 5 6 Frequency 15 22 28 35 42 34 24 Compute the mean, median and mode... 4. Define correlation. Calculate and analyze the correlation coefficient between the number of study hours and the number of sleeping hours of different students. No of study Hrs 2 4 6 8 10 No of Sleeping Hrs 10 9 8 7 6 Also find coefficient of determination and interpret it. 5. Define regression. The following table gives information on ages and cholesterol levels for sample of 10 men. Age 58 69 43 39 63 52 47 31 74 36 Cholesterol level 189 235 193 177 154 191 213 165 198 181 6. Define binomial distribution. During one stage in the manufacture of integrated circuit chips, a coating must be applied. If 70% of chips received a thick enough coating, find the probability that among 15 chips i) at least 12 will have thick enough coatings ii) exactly 10 will have thick enough coatings 7. In measuring reaction time, a psychologist estimates that the standard deviation is 0.95 sec, how large a sample of measurements must be taken in order to be 95% confident that the error his estimate of mean will not exceed 0.01 second? 8. Define sampling. A population consists of the four numbers 1, 3, 4, 8. (1) Write down all possible sample size of two without replacement. (ii) Show that sample mean is an unbiased estimate of population mean. Don’t Forget to Follow Uni Bytes
Prepared by Uni Bytes / www.unibytes.xyz Don't use our content without permission. Group C Attempt any TWO questions 9. An analysis of monthly wages paid to workers in two firms A and B belonging to the same industry gives the following results: Frim A Firm B No of workers 500 600 Average monthly wage 186 175 Variance of distribution of wages 81 100 i) Which firm A or B, has a larger wage bill? ii) In which firm, is there greater variability in individual wage? iii) Calculate combined mean and combined variance of the wage of firm A and B. 10. The length of human pregnancies from conception to birth approximates a normal distribution with a mean of 266 days and a standard deviation of 16 days. (i) What probability of all pregnancies will last between 240 and 270 days? (i) What probability of all pregnancies will last more than 275 days? (iii) What probability of all pregnancies will last less than 272 days? 11. Define ANOVA. Given data, using one-way ANOVA test the hypothesis that means of three samples are equal Sample I 4 5 6 5 Sample II 7 5 6 5 Sample III 4 8 9 2 Don’t Forget to Follow Uni Bytes