In: Statistics and Probability
Test the claim that the proportion of men who own cats is
significantly different than the proportion of women who own cats
at the 0.2 significance level.
The null and alternative hypothesis would be:
H0:pM=pFH0:pM=pF
H1:pM>pFH1:pM>pF
H0:pM=pFH0:pM=pF
H1:pM<pFH1:pM<pF
H0:pM=pFH0:pM=pF
H1:pM≠pFH1:pM≠pF
H0:μM=μFH0:μM=μF
H1:μM<μFH1:μM<μF
H0:μM=μFH0:μM=μF
H1:μM>μFH1:μM>μF
H0:μM=μFH0:μM=μF
H1:μM≠μFH1:μM≠μF
The test is:
two-tailed
left-tailed
right-tailed
Based on a sample of 40 men, 30% owned cats
Based on a sample of 20 women, 50% owned cats
The test statistic is: (to 2 decimals)
The p-value is: (to 2 decimals)
Based on this we:
Answer)
Null hypothesis usually have three types of claim.
1) >= (greater than or equal to )
2) <= (less than or equal to)
3) = (equal to )
Alternate hypothesis Ha have
1) < (less than (left tailed ))
2) > (greater than (right tailed))
3) not equal to (two tailed))
Both are exactly opposite of each other and in some cases we just use = sign for null hypothesis.
1)
H0:pM=pFH0:pM=pF
H1:pM≠pFH1:pM≠pF
The test is two tailed.
N1 = 40, P1 = 0.3.
N2 = 20, P2 = 0.5.
First we need to check the conditions of normality that is if n1p1 and n1*(1-p1) and n2*p2 and n2*(1-p2) all are greater than equal to 5 or not
N1*p1 = 12
N1*(1-p1) = 28
N2*p2 = 10
N2*(1-p2) = 10
All the conditions are met so we can use standard normal z table to conduct the test
Test statistics z = (P1-P2)/standard error
Standard error = √{p*(1-p)}*√{(1/n1)+(1/n2)}
P = pooled proportion = [(p1*n1)+(p2*n2)]/[n1+n2]
After substitution
Test statistics z = -1.52
From z table, P(Z<-1.52) = 0.0643
Sjnce test is two tailed,
So, P-Value = 0.0643*2 = 0.1286
As the obtained P-Value is less than the given significance 0.2.
Reject the null hypothesis.