Chi Square Test
Hypothesis Testing
T Test Z test Chi Square test
Hello Students !!
In this video lecture we will Solve IGNOU BCS040 December 2021 Question Paper.
A pharmacologist measured the amount of dopamine (no. of moles/gm) in the brains of each of 10 rats. The observed data is given below :
6.8, 7.0, 5.3, 6.0, 5.9, 5.6, 6.8, 7.4, 6.2, 7.0
Calculate :
(i) The mean and standard deviation
(ii) Coefficient of variation
2. In a certain population of women, 5% have breast cancer, 15% are smokers and 3% are smokers as well as have breast cancer. A woman is selected and random from the population. What is the probability that she has breast cancer or she is a smoker ?
3. The pulse rate of 6 people was recorded before and after taking a new drug, which are given below : Pulse Rate
Before Drug 68 71 84 93 67 74
After Drug 71 70 82 97 73 80
On the basis of the above information, can you conclude that there is a significant effect of the new drug to increase the pulse rate at 1% level of significance ? [Given that 5 (0.01) t = 4.032]
4. A company produces electric bulbs. To estimate the average life of the bulbs, the quality inspector selects 80 bulbs randomly. She finds that the average life of these bulbs is 50 hours. Find the population average life of the electric bulbs produced by the company using 95% confidence limits.
5. The average yield of wheat crop (in quintals/ha) pertaining to fields of 40 villages in a district is given below : 20, 21, 32, 41, 55, 22, 64, 42, 28, 35, 25, 25, 24, 32, 75, 28, 29, 38, 19, 19, 16, 28, 30, 29, 29, 19, 37, 34, 31, 35, 29, 19, 27, 42, 39, 11, 26, 21, 45, 61.
Select a systematic random sample of 10 units and find the average of it.
6. The yearly water consumption in a small city for ten years is given below. Determine the trend values by using a 3-yearly moving average. Also plot the values and interpret the results :
7. Twenty individuals were randomly assigned to four different production processes. Production of units per hour for the four processes are given below :
Process I 33 30 28 29 30
Process II 33 35 30 38 34
Process III 28 38 30 34 30
Process IV 34 28 29 26 28
Determine if there is significant difference in the average production units per hour for the four types of production processes. [Given that (3,16)5% F = 3.24].
8. A population of size 10000 is divided into 4 strata. Their sizes and standard deviations are given below : Strata I II III IV Ni = Sizes 5000 1000 2000 2000 Si 25 10 15 20
A stratified random sample of size 500 is to be drawn from this population. Determine the
sizes of samples from these strata, in case :
(i) Proportional allocation is used
(ii) Neyman’s optimum allocation is used.
9. 1000 students at college level were graded according to their IQ levels and the economic condition of their parents, as follows : Economic Condition IQ Level
High Low Total
Rich 230 170 400
Poor 470 130 600
Total 700 300 1000
Test the hypothesis that IQ levels are independent of the economic conditions at 1%level of significance. [Given that 2 1 (0.01) 6.63]
10. A gynecologist recorded the blood pressure (BP) of her patients and collected the following
data : Age (in years) BP (in mmHg)
23 65
24 60
25 62
26 70
28 70
29 73
31 75
35 83
40 90
Fit the regression line for the given data and estimate BP if age of the patient is 38 years.