National College of Computer Studies (NCCS)



Group “A”

Brief Answer Questions: [4(2=8]

1. A bag contains 4 red, 5 green and 6 white balls. If two balls are drawn at random, what is the probability that none of them is green?

2. A random sample of 50 gave a mean of 7.5 kg and a Standard Deviation of 1.5 kg. Find 95% confidence limits for population mean.

3. Out of 100 families of 3 children each, how many families would you expect to have two boys and one girls, assuming that boys and girls are equally likely?

4. Draw the less than ogive from the following frequency distribution.

|Mid Point : |5 |10 |15 |20 |25 |30 |

|Frequency : |1 |3 |5 |10 |2 |1 |

Group “B”

Short Answer Questions: [4(3=12]

5. The mark distribution of 104 students is given below.

|Mid Point : |10 |20 |30 |40 |50 |60 |70 |

|No of Students : |7 |8 |13 |29 |35 |9 |3 |

Find the pass marks if 78 students passed the examination

6. A population consists of number 1, 3, 5, 7, 9. Draw all possible samples of size two which can be drawn from the population with-out replacement, show that the mean of the sampling distribution of the sample mean is equal to population mean. Also show that standard deviation of sampling distribution is less than population standard deviation.

7. Define sampling. Describe various method of sampling techniques.

8. It is claimed that tea is more popular than coffee in Kathmandu district, if in a random sample of 600 person, 310 were regular consumers of tea. Is the claim justified at 5% level of significance?

Group “C”

Comprehensive Answer Questions: [2(8=16]

9. From the data given below, find:

a) Coefficient of correlation between age of husband and wives.

b) The two regression equations.

c) The most likely age of husband when wife’s age is 25 and the most likely age of wife when husband’s age is 30.

|Age of Husband: |22 |

| |A |B |

|5.0 - 9.9 |2 |9 |

|10.0 - 14.9 |9 |11 |

|15.0 - 19.9 |29 |18 |

|20.0 - 24.9 |54 |32 |

|25.0 - 29.9 |11 |27 |

|30.0 – 34.9 |5 |13 |

Which set of bags has more uniform pressure? If prices are the same, which manufacturer’s bags would

be preferred by the buyer? Why?

Group “A”

Brief Answer Questions: [4(2=8]

1. A bag contain 8 green and 10 white balls. Two balls are drawn. What is the probability one is green and other is white?

2. A simple random sample of size 31 is drawn without replacement from a finite population consisting of 250 units. If the number of defective units in the population be 20. Find the S.E. of sample proportion.

3. If 4% of the bulbs manufactured by a company are defective, find the probability that in a sample of 125 bulbs, 3 bulbs will be defective.

4. Following is the distribution of marks obtain by 50 students. Plot a histogram for these data.

|Marks |20-29 |30-39 |40-49 |50-59 |60-69 |70-79 |

|No. of Students |5 |10 |20 |8 |6 |1 |

Group “B”

Short Answer Questions [4(3=12]

5. The following table represents the marks of 100 students.

|Marks |0-20 |20-40 |40-60 |60-80 |80-100 |

|No. of students |14 |- |27 |- |15 |

If the median mark is 48, find the missing frequencies and the mean marks of all 100 students.

6. A population consists of five numbers 3, 5, 6, 7, 8. Draw all possible samples of size two which can be drawn from the population with-out replacement, show that the mean of the sampling distribution of the sample mean is equal to population mean. Also show that standard deviation of sampling distribution is less than population standard deviation.

7. What is sampling technique? Describe various methods of sampling techniques.

8. A random sample of 100 students gave a mean weight of 58 kgs and standard deviation of 4 kgs. Test the hypothesis that the mean weight of all the students is less than 60 kgs.

Group “C”

Comprehensive Answer Questions: [2(8=16]

9. The advertisement expenses and the sales of a new product are recorded as below:

|Adv. Exp (Rs. ’000) |1 |5 |6 |8 |10 |

|Sales (Rs. ’000) |50 |60 |80 |100 |110 |

From the data given above, find:

a) The two regression equations.

b) The sales when the advertising expenses is Rs. 15,000 and advertising expenses when the sales is

Rs. 40,000.

c) The correlation coefficient.

10. Two brands of tyres are tested and the corresponding life is given below.

|Life (’000 km) |No of companies |

| |Brand Modi |Brand Yakohama |

|0-4 |4 |9 |

|5-9 |26 |16 |

|10-14 |46 |40 |

|15-19 |18 |19 |

|20-24 |10 |11 |

|25-29 |2 |5 |

Which brand of tyre has more uniform life? If you have to buy, in which type of tyre company you will go and

why? Give reason.

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National College of Computer Studies

(NCCS-College of IT & Management)

Final Examination (2015)

|BIM/Third Semester/ STT 201: Business Statistics |

Candidates are required to answer all the questions in their own words as far as practicable.

Full Marks: 36

Pass Marks: 18

Time: 2 Hours

Set A

Set B

Full Marks: 36

Pass Marks: 18

Time: 2 Hours

National College of Computer Studies

(NCCS-College of IT & Management)

Final Examination (2015)

|BIM/Third Semester/ STT 201: Business Statistics |

Candidates are required to answer all the questions in their own words as far as practicable.

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