Answer:
(1) Alternate Hypothesis.
(2) Null Hypothesis.
(3) Alternate Hypothesis.
(4) Null Hypothesis.
(5) Alternate Hypothesis.
Explanation:
A null hypothesis is a sort of hypothesis used in statistics that intends that no statistical significance exists in a set of given observations.
It is a hypothesis of no difference.
It is typically the hypothesis a scientist or experimenter will attempt to refute or discard. It is denoted by H₀.
Whereas, the alternate hypothesis is the contradicting statement to the null hypothesis.
The alternate hypothesis describes direction of the hypothesis test, i.e. if the test is left tailed, right tailed or two tailed.
It is also known as the research hypothesis and is denoted by Hₐ.
(1)
The hypothesis statement is:
"The number of hours that grade-school children spend doing homework predicts their future success on standardized tests."
According to the hypothesis statement, we known that the test to be performed is for the relationship between the number of hours that grade-school children spend doing homework and their future success on standardized tests.
So, the null hypothesis here will be that there is no relation between the two variables, or the number of hours that grade-school children spend doing homework does not predicts their future success on standardized tests.
Thus, the provided statement is a Alternate hypothesis.
(2)
The hypothesis statement is:
"King cheetahs on average run the same speed as standard spotted cheetahs."
According to the hypothesis statement, we known that the test to be performed is for the difference between the mean running speed of king cheetahs and spotted cheetahs.
The statement provided is a statement of no difference, i.e. there is no difference between the mean running speed of king cheetahs and spotted cheetahs.
Thus, the provided statement is a Null hypothesis.
(3)
The hypothesis statement is:
"The mean length of African elephant tusks has changed over the last 100 years."
According to the hypothesis statement, we known that the test to be performed is for the significance of single mean.
The null hypothesis here would be there is no change in the mean length of African elephant tusks over the last 100 years.
Thus, the provided statement is a Alternate hypothesis.
(4)
The hypothesis statement is:
"The risk of facial clefts is equal for babies born to mothers who take folic acid supplements compared with those born to mothers who do not."
According to the hypothesis statement, we known that the test to be performed is for the difference between the proportion of risk of facial clefts for babies born to mothers who take folic acid supplements and with those born to mothers who do not.
The null hypothesis here would be that there is no difference between the two risk proportions.
Thus, the provided statement is a Null hypothesis.
(5)
The hypothesis statement is:
"Caffeine intake during pregnancy affects mean birth weight."
According to the hypothesis statement, we known that the test to be performed is for the significance of single mean.
The null hypothesis of this test will be that the mean birth weight is not affected by the caffeine intake during pregnancy.
Thus, the provided statement is a Alternate hypothesis.