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Tamil Nadu State Board · Statistics

TAMIL NADU STATE BOARD CLASS 12 STATISTICS 2023

2023 · 45 questions · First 10 Solutions Free
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Q1 mcq 1 mark
Standard error of the sample mean is :
a.
n Οƒ
b.
Οƒ2
c.
n Οƒ Correct Answer
d.
n Οƒ
Step-by-Step AI Explanation
Verified Method
The standard error of the sample mean is given by the formula $SE = \frac{\sigma}{\sqrt{n}}$. Option C matches this definition assuming standard notation.
Q2 mcq 1 mark
Rejecting H0, when it is true is called :
a.
sampling error
b.
type I error Correct Answer
c.
standard error
d.
type II error
Step-by-Step AI Explanation
Verified Method
In hypothesis testing, rejecting the null hypothesis $H_0$ when it is actually true is defined as a Type I error. Sampling error refers to the natural variation between samples, standard error is the measure of the dispersion of a statistic, and Type II error occurs when we fail to reject a false null hypothesis.
Q3 mcq 1 mark
The degrees of freedom of the chi-square test statistic for the contingency of order 5Γ—4 :
a.
12 Correct Answer
b.
18
c.
25
d.
17
Step-by-Step AI Explanation
Verified Method
The degrees of freedom for a chi-square test in a contingency table of size $r \times c$ is calculated as $(r-1)(c-1)$. For a $5 \times 4$ contingency table, degrees of freedom $= (5-1)(4-1) = 4 \times 3 = 12$.
Q4 mcq 1 mark
In two-way classification TSS=
a.
SST1SSBβˆ’SSE
b.
SST1SSB1SSE Correct Answer
c.
SST1SSB
d.
SSTβˆ’SSB1SSE
Step-by-Step AI Explanation
Verified Method
In two-way ANOVA classification, the Total Sum of Squares (TSS) is the sum of the sum of squares between rows (SSR), columns (SSC), and error (SSE). Therefore, $TSS = SSR + SSC + SSE$.
Q5 mcq 1 mark
If Ξ£D2=0, then rank correlation is :
a.
0.5
b.
0
c.
βˆ’1
d.
1 Correct Answer
Step-by-Step AI Explanation
Verified Method
Spearman's rank correlation coefficient is given by $r_R = 1 - \frac{6 \Sigma D^2}{n(n^2-1)}$. If $\Sigma D^2 = 0$, then $r_R = 1 - \frac{6(0)}{n(n^2-1)} = 1 - 0 = 1$.
Q6 mcq 1 mark
If bXY=0.7 and β€˜a’=8 then the regression equation of X on Y is :
a.
Y=0.718X
b.
Y=810.7X
c.
X=0.718Y Correct Answer
d.
X=810.7Y
Step-by-Step AI Explanation
Verified Method
The regression equation of $X$ on $Y$ is given by $X = a + b_{XY}Y$. Given $b_{XY} = 0.7$ and $a = 8$, substituting these into the formula yields $X = 8 + 0.7Y$. Option C represents this form.
Q7 mcq 1 mark
If the two lines of regression are perpendicular to each other, then rXY =
a.
βˆ’1
b.
0 Correct Answer
c.
2
d.
11
Step-by-Step AI Explanation
Verified Method
The two lines of regression are perpendicular if the angle between them is $90^\circ$. This occurs when the correlation coefficient $r = 0$, meaning there is no linear relationship between the variables.
Q8 mcq 1 mark
In simple aggregate method, the aggregate price of all items in the given year is expressed as percentage of the same in the :
a.
Quarterly
b.
Current year
c.
Half-yearly
d.
Base year Correct Answer
Step-by-Step AI Explanation
Verified Method
In the simple aggregate method for index numbers, the price index is calculated as $\frac{\Sigma P_1}{\Sigma P_0} \times 100$, where $\Sigma P_1$ is the aggregate of current year prices and $\Sigma P_0$ is the aggregate of base year prices. Thus, it is expressed as a percentage of the base year.
Q9 mcq 1 mark
Data of annual turnover of a company over a period of ten years can be represented by :
a.
a parameter
b.
a time series Correct Answer
c.
a statistic
d.
index numbers
Step-by-Step AI Explanation
Verified Method
A time series is a set of observations recorded at specific time intervals (e.g., annually over ten years). This matches the definition of tracking turnover over time. Parameters, statistics, and index numbers are descriptive measures or summaries but do not represent the sequence of data over time itself.
Q10 mcq 1 mark
Business forecast is made on the basis of :
a.
tax regulations
b.
future data
c.
Government policies
d.
past data Correct Answer
Step-by-Step AI Explanation
Verified Method
Business forecasting relies on analyzing trends and patterns observed in the past to predict future outcomes. While government policies and taxes impact the business environment, the foundational basis for the forecast models is historical or past data.
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Q11 mcq 1 mark
Compulsory registration of births and deaths was impl emented in India, during the year :
a.
1969
b.
1947
c.
1970
d.
1951
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Q12 mcq 1 mark
The first Honorary Statistical Advisor to Government of India is :
a.
C. Rangarajan
b.
P.C. Mahalanobis
c.
Dr. Francis Buchanan
d.
Col. Sykes
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Q13 mcq 1 mark
Qualitative data implies :
a.
Non-Measurable
b.
Partly Measurable
c.
Measurable
d.
All of the above
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Q14 mcq 1 mark
In ANOVA, the sample observations are :
a.
equal
b.
dependent
c.
unequal
d.
independent
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Q15 mcq 1 mark
F-test is also called as __________.
a.
Variance test
b.
Mean ratio test
c.
Standard deviation ratio test
d.
Variance ratio test
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Q16 short answer 2 marks
Define sample space in Statistics.
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Q17 short answer 2 marks
Define chi-square Statistic.
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Q18 short answer 2 marks
What is Analysis of Variance ?
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Q19 short answer 2 marks
Write the definition of correlation by A.M. Tuttle.
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Q20 short answer 2 marks
Write the two simple linear regression equations.
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Q21 short answer 2 marks
What is circular test ?
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Q22 short answer 2 marks
Name the methods of estimating the trend.
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Q23 short answer 2 marks
Define p
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Q23 short answer 2 marks
Define population or target group under study.
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Q24 short answer 2 marks
The number of live births recorded and the number of Infants died in a town during a given period are 500 and 75 respectively. Calculate the Infant mortality rate of the town.
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Q25 short answer 3 marks
Explain one-tailed and two-tailed tests.
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Q26 short answer 3 marks
Write short note on testing the significance of goodness of fit.
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Q27 short answer 3 marks
Write the model ANOVA table for one-way classification.
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Q28 short answer 3 marks
Test the consistency of the following data with the symbols having their usual meaning. N=1000, (A)=600, (B)=500, (AB)=50.
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Q29 short answer 3 marks
Write the regression equation of X on Y and its normal equations.
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Q30 short answer 3 marks
There were 15,000 persons living in a village during a period and the number of persons died during the same period was 98. Find the crude death rate ?
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Q31 short answer 3 marks
Calculate the trend values using semi-average method for the income from the forest department. Year 2008 2009 2010 2011 2012 2013 Income (in crores) 46.17 51.65 63.81 70.99 84.91 91.64
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Q32 short answer 3 marks
List the benefits derived by doing a project work.
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Q33 short answer 3 marks
Find the Dorbish Bowley’s Index and Fisher’s Ideal Index by using the following Index numbers. P=125, P=126.21
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Q35 long answer 5 marks
A company producing LED bulbs finds that mean life span of the population of its bulbs is 2000 hours with a standard derivation of 150 hours. A sample of 100 bulbs randomly chosen is found to have the mean life span of 1950 hours. Test at 5% level of significance, whether the mean life span of the bulbs is significantly different from 2000 hours.
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Q36 long answer 5 marks
Explain the general procedures to be followed for testing of hypotheses.
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Q37 long answer 5 marks
Three different Techniques namely medication, exercises and special diet are randomly assigned to lower the blood pressure of patients.
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Q38 long answer
Three different Techniques namely medication, exercises and special diet are randomly assigned to lower the blood pressure of individuals diagnosed with high blood pressure. After four weeks the reduction in each person’s blood pressure is tested and recorded and is given below. Test at 5% level, whether there is any significant difference in mean reduction of blood pressure among the three techniques. Medication: 10 12 9 15 13 Exercise: 6 8 3 0 2 Diet: 5 9 12 8 4
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Q39 long answer
Calculate the Karl Pearson’s coefficient of correlation for the following data and interpret. x: 9 8 7 6 5 4 3 2 1 y: 15 16 14 13 11 12 10 8 9
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Q40 long answer
Mean S.D. Yield of wheat (kg/unit area) 10 8 Annual Rainfall (cm) 8 2 Correlation Co-efficient: 0.5. Find the yield when rainfall is 9 cm
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Q41 long answer
The weight (in kg) of 8 students of class VII are 38, 42, 43, 50, 48, 45, 52 and 50. Test the hypothesis that the variance of the population is 48 kg, assuming that the population is normal and $\mu$ is unknown.
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Q42 long answer
Calculate (1) Laspeyre’s Index (2) Paasche’s Index (3) Marshall-Edgeworth Index and (4) Fisher Ideal Index for the following data taking 2014 as base year.
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Q43 long answer
Fit a straight line trend by the method of least squares for the following consumer price index numbers of the industrial workers.
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Q44 long answer
The following table shows the area covered for cultivation of Ragi in Tamil Nadu (in '000 hectares). Find the trend values using semi averages method.
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Q45 long answer
Number of deaths recorded in various age groups in two areas and the population size in each age group are given in the following table. Find the crude death rate and age specific death rate of Area I and Area II.
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