Shared Flashcard Set

Details

S11.4 - Inference for Two Population Standard Deviations
Inference for Two Population Standard Deviations
20
Mathematics
Graduate
11/11/2013

Additional Mathematics Flashcards

 


 

Cards

Term
To test hypotheses regarding population standard deviations, we use
Definition
Fisher's f-distribution
Term
2 requirements for testing hypotheses regarding two population standard deviations
Definition
1. The samples are independent simple random variables
2. The populations from which the samples are drawn are normally distributed
*These testing procedures are not robust
Term
sigmai^2 =
Definition
Variance for population i
Term
si^2 =
Definition
Sample variance for population i
Term
ni =
Definition
Sample size for population i
Term
F =
Definition
s1^2/s2^2
Term
1. Characteristics of the f-distribution
Definition
The f-distribution is not symmetric; it is skewed right
Term
2. Characteristics of the f-distribution
Definition
The shape of the f-distribution depends on the degrees of freedom in the numerator and the denominator
Term
3. Characteristics of the f-distribution
Definition
The total are under the curve is 1
Term
4. Characteristics of the f-distribution
Definition
The values of F are always greater than or equal to zero
Term
F-statistic is found by using
Definition
Degrees of freedom in the numerator/degrees of freedom in denominator, then find the f-statistic in critical value table according to alpha and degrees of freedom
Term
3 assumptions for test hypotheses regarding two population sd's
Definition
1. The samples are obtained using simple random sampling
2. The sample data are independent
3. The populations from which the samples are drawn are normally distributed
*Not robust
Term
Two-tailed test, two population sd's
H0:
H1:
Definition
H0: sigma1 = sigma2
H1: sigma1 not=to sigma2
Term
Left-tailed test, two population sd's
H0:
H1:
Definition
H0: sigma1 = sigma2
H1: sigma1 < sigma2
Term
Right-tailed test, two population sd's
H0:
H1:
Definition
H0: sigma1 = sigma2
H1: sigma1 > sigma2
Term
Two-tailed test, classical approach
If F0 > F(alpha/2),n1-1,n2-1, then
Definition
Reject the null
Term
Left-tailed test, classical approach
If F0 < F(1-alpha),n1-1,n2-1, then
Definition
Reject the null
Term
Right-tailed test, classical approach
If F0 > F(alpha),n1-1,n2-1, then
Definition
Reject the null
Term
P-value approach
If p-value < alpha, then
Definition
Reject the null
Term
P-value approach
If p-value > alpha, then
Definition
Fail to reject null
Supporting users have an ad free experience!