National University Bangladesh
Business Statistics question
Hons 3rd year exam 2020
Subject Code: 232603
Subject: Business Statistics
Answer any ten questions: 1 × 10 = 10
a) What is pie-chart?
And: A Pie-chart is formed by making off a portion of the pie corresponding to each characteristic being displayed.
b) What is primary data?
Aus: Primary data that have been collected from the origin of the fields is called primary data.
c) What is arithmetic mean?
Ans: An Arithmetic Mean is a numerical value obtained by dividing the sum of values of all the observations by the total number of observations.
d) Calculate range of the followings: 2,3,4,-2-4.
Ans: Range=Highest value-Lowest value
e) How many types of skewness?
Ans: Skewness is of two types as:
i) Positive Skewness,
ii) Negative Skewness
f) What is rank correlation?
Ans: The Co-efficient of correlation between two sets of rank is called rank correlation.
g) Define standard deviation.
Ans: The standard deviation is the positive square root of the mean of the squared deviations from their mean of a set of value.
h) What is time series?
Ans: When data are arranged in against of time, it is called the time series. Ans: The simplest device for studying correlation in two variables is a special type of at chart
i) What is scatter diagram?
j) What is histogram?
Ans: Histogram is a Suitable graph for representing the frequency distribution of a continuous
k) Define null hypothesis.
Ans: The hypothesis about a Population Parameter we wish to test is called a null hypothesis.
l) What is critical value?
Ans: The value of the standard statistic (Z or t) beyond which we reject the null hypothesis
Answer any five questions: 4 × 5 = 20
2. What is the role of statistics in managerial decision making?
3. Show the difference between primary data and secondary data.
4. Distinguish between price index and cost of living index.
5. The average marks of 39 students of a class are 50. The marks obtained by 40th student are 39 more than the average marks of all the 40 students. Find the mean marks of all the 40 students.
6. What are the properties of a good measure of dispersion?
7. From the following data, calculate trend values using 3-yearly moving average:
8. From the following data calculate mean deviation
16, 20, 22, 19, 18, 20, 30, 18, 20, 22
9. Five cards are drawn from a packet of well-shuffed cards. Find the probability that 4 cards are aces.
Answer any five questions: 10 × 5 = 50
10. Calculate the mode from the following data:
11. Find out skewness of the following data and comment on the results:
12. Define dispersion. Discuss the different measures of dispersion.
13. Find out the co-efficient of correlation of the following data and comment on the result:
14.Fit a trend line by the method of least squares to the following data:
Plot the given data on a graph paper. Showing also the trend line, estimate the sales for year 2021.
15. Compute Fisher’s Index Number from the following data and verify the time reversal test and factor reversal test:
16. Three unbiased coins are thrown at a time, construct a sample space. What is the probability of getting
(i) At best two heads;
(ii) At least two heads.
17. Calculate the skewness and curtosis from the following information and comment on the result: