BCA 3rd Semester

Probability and Statistics 2022 Board Question Paper

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Tribhuvan university

Bachelor In Computer Application

Course Title:Probability and Statistics

Code No:

Semester:III

2022

Full Marks:60 Pass Marks:24 Time:3 hours

Candidates are required to answer the question in their own words as far as possible.

Group B
Attempt any SIX question.
[6x5=30]
11.

Differentiate between Convenient sampling and Systematic random sampling with suitable examples.

12.

From the following data, find Mean and Median. Then use an empirical relation across mean, median and mode to find Mode.

Age group10-2020-3030-4040-5050-60
No.of months (f)103517129

13.

When Mean is 34.69 for 65 total observations, find the missing frequency from the following data.

Expense-clases in thousand rupees10-2020-3030-4040-5050-60
No of 5 star hotel establishment9122510?

14.

Use Karl Pearson’s correlation method to examine the relationship between marks obtained in two subjects:

StudentsABCDEFGHIJ
Statistics42516557562819243380
Mathematics42616654572829213587

15.

The number of defective articles is found to be 2% in a lot of 300 sample articles per day, then find out following probabilities using suitable probability distribution that
(i) There are exactly two defective articles per day
(ii) There are at least 2 defective articles per day.

16.

Six coins are tossed 500 times such that probability of getting a head is 21% in each toss.Fit a Binomial distribution for a number of heads with the following frequency distribution:

X0123456total
f(frequency)165807055455035500

17.

In a Hospital, the height of patients follows normal distribution with mean height of 53 inches with standard deviation of 3 inches.Then find out the following probabilities of heights of patients that:
i) less than 57 inches,
ii) more than 64 inches,
iii) between 50 and 56 inches. Use Normal table.

Group C

Attempt any TWO questions

[2x10=20]
18.

Automobile Company Sells Cars of different model during a year. Data are presented in the following table:

Piece of cars12134015167080901577
Demands of cars2428121310654115
Now, fit a linear regression model of demand of cars. Interpret the intercept and slope of the model. Also, find the demand of cars when price is 25 lakhs. Also, find the coefficient of determination and interpret it.

19.

An analysis of daily wages, paid to workers in two firms A and B belonging to the same industry, gives the following results:

YeasFirm AFirm B
No of workers200300
CV of Daily Wages56
Variance of distribution of wages6786
a) Which firm A or B has a larger wage bill?
b) In which firm, A or B, is there a greater consistency or uniformity or variability in individual wages?
c) Find out the combined average of both firms A and B.

20.

Perform a one-way ANOVA to differentiate average sales of computers from three electronic shops as given below at 5% level of significance:

Shop A1015182135
Shop B2345455557
Shop C4567787890
Which shop has a greater average sale of computers? Use F table for Ftab (2, 12) at 5% level.