F-Distributions and Its Applications

IMPORTANT

F-Distributions and Its Applications: Overview

This Topic covers sub-topics such as Analysis of Variance, F-Statistic, Two-way Analysis of Variance, F-Distribution, Population Variance, One Way Analysis of Variance and, Test For Normal Population Variances

Important Questions on F-Distributions and Its Applications

HARD
IMPORTANT

The given operators are tested for their efficiency in terms of number of units produced per day by five different types of machines.

State null hypothesis and alternative hypothesis.

Test at 5% level of significance whether the operators and the machines differ in terms of their efficiency? 

Operators Machine types
A B C D E
I 9 10 8 10 7
II 12 13 8 9 12
III 7 8 6 8 8
IV 5 5 3 5 14

HARD
IMPORTANT

A farmer applies three types of fertilizers on four separate plots. The figures on yield per acre are tabulated below.

Fertilizer Plots
A B C D
Nitrogen 6 4 8.5 5.5
Potash  7 6 5.5 9.5
Phosphate 8 5 10 9

Test whether there is any significant difference among mean yields of different plots and among different fertilizers and test the hypothesis.

HARD
IMPORTANT

The following data refer to the yield of wheat in quintals on plots of equal area in two agricultural blocks A and B.

  Number of plots Mean yield Sample variance
Block A 10 80 50
Block B 8 54 40

Is the variance of yield for block A is greater than that of block B at 5% level of significance.(Answer H0 is rejected/not rejected)

HARD
IMPORTANT

A test was given to five students taken at random from XI class of three schools of a town. The individual scores are

School I 9 7 6.5 5 7.5
School II 7 4 5 4.5 4.5
School III 6 5 6 6.5 6.5

Carry out the one-way ANOVA. (Answer H0 is rejected/not rejected)

 

HARD
IMPORTANT

Check whether the  H0 is rejected/not rejected.

A sample of 7 observations, the sum of the squares of deviations of the sample values from its sample mean was 74.4. In another sample of 11 observations it was 100.6. Test whether the two population variances are equal at 5% level.

HARD
IMPORTANT

A home gardener wishes to determine the effects of four fertilizers on the average number of tomatoes produced. Test at 5% level of significance the hypothesis that the fertilizers A, B, C and D have equal average yields. 

A 14 10 12 16 17
B 9 11 12 8 10
C 16 15 14 10 18
D 10 11 11 13 8

 

HARD
IMPORTANT

Three processes XY and Z are tested to see whether their outputs are equivalent. The following observations on outputs were made.

X 10 13 12 11 10 14 15 13
Y 9 11 10 12 13      
Z 11 10 15 14 12 13    

Carry out the one-way analysis of variance and state your conclusion.

[Suppose if your answer is H0 is accepted then write YES in answer box and if your answer is H0 is rejected, then write NO in answer box]

HARD
IMPORTANT

A test was given to five students taken at random from XII class of three schools of a town. The individual scores are

School I 9 7 6 5 8
School II 7 4 5 4 5
School III 6 5 6 7 6

Carry out the one-way ANOVA. (Answer H0 is rejected/not rejected)

 

HARD
IMPORTANT

A farmer applies three types of fertilizers on four separate plots. The figures on yield per acre are tabulated below.

Fertilizer Plots
A B C D
Nitrogen 6 4 8 6
Potash  7 6 6 9
Phosphate 8 5 10 9

Test whether there is any significant difference among mean yields of different plots and among different fertilizers and test the hypothesis.

HARD
IMPORTANT

The given operators are tested for their efficiency in terms of number of units produced per day by five different types of machines.

State null hypothesis and alternative hypothesis.

Test at 5% level of significance whether the operators and the machines differ in terms of their efficiency? 

Operators Machine types
A B C D E
I 8 10 7 12 6
II 12 13 8 9 12
III 7 8 6 8 8
IV 5 5 3 5 14

EASY
IMPORTANT

For test of significance for two normal population variance, find the test statistic value of given data.

Sample I: n1=10∑(xi-x¯)2=90, sample II:  n2=17,∑(yi-y¯)2=64.

EASY
IMPORTANT

For test of significance for two normal population variance, sx2=30 and sy2=20. Find the test statistic value for the given data.

EASY
IMPORTANT

For test of significance for two normal population variance, sx2=60 and sy2=50. Find the test statistic value for the given data.

EASY
IMPORTANT

For test of significance for two normal population variance, a sample I of n1=11 observations, the sum of the squares of deviations of the sample values from its sample mean was ∑(xi-x¯)2=50. In another sample II of n2=21 observations it was ∑(yi-y¯)2=200. Find the test statistic value of given data.

EASY
IMPORTANT

For test of significance for two normal population variance, a sample I of n1=8 observations, the sum of the squares of deviations of the sample values from its sample mean was ∑(xi-x¯)2=84.4. In another sample II of n2=10 observations it was ∑(yi-y¯)2=102.6. Find the test statistic value of given data.

EASY
IMPORTANT

Find population variance for the following data:

∑i=1Nxi-μ2=300, N=20

EASY
IMPORTANT

Find population variance for the following data:

∑i=1Nxi-μ2=250, N=10

EASY
IMPORTANT

Find population variance for the following data:

∑i=1Nxi-μ2=100, N=5

EASY
IMPORTANT

Difference between population variance and sample variance.