Answer:
C. H0 : p = 0.8 H 1 : p ≠ 0.8
The test is:_____.
c. two-tailed
The test statistic is:______p ± z (base alpha by 2) 
The p-value is:_____. 0.09887
Based on this we:_____.
B. Reject the null hypothesis.
Step-by-step explanation:
We formulate null and alternative hypotheses as proportion of people who own cats is significantly different than 80%.
H0 : p = 0.8 H 1 : p ≠ 0.8
The alternative hypothesis H1 is that the 80% of the proportion is different and null hypothesis is , it is same.
For a two tailed test for significance level = 0.2 we have critical value ± 1.28.
We have alpha equal to 0.2 for a two tailed test . We divided alpha with 2 to get the answer for a two tailed test. When divided by two it gives 0.1 and the corresponding value is ± 1.28
The test statistic is
p ± z (base alpha by 2) 
Where p = 0.8 , q = 1-p= 1-0.8= 0.2
n= 200
Putting the values
0.8 ± 1.28 
0.8 ± 0.03620
0.8362, 0.7638
As the calculated value of z lies within the critical region we reject the null hypothesis.
Answer:
Orinal number of cats= 171
Step-by-step explanation:
Giving the following information:
Decrease in population= 30%
Current population= 120
<u>To calculate the original number of cats, we need to use the following formula:</u>
Orinal number of cats= current population / (1 - decrease)
Orinal number of cats= 120 / (1 - 0.3)
Orinal number of cats= 171
Correct answer is: P(x<6) is 0.123 and it is usual.
Solution:-
Given that the time a person takes to decide which shoes to purchase follows normal distribution. Which has mean = 8.21 minutes and standard deviation 1.90
Then probability of individual takes less than 6 minutes is
P(X<6) = 
= 
= 0.1230
Typically we say an event with a probability less than 5% is unusual.
But here P(X<6) = 0.123 is greater than 5% hence this is usual.
I think the answer is option 3.