In Clinical Trials
Hypothesis tests are often used in clinical trials to determine whether some new treatment, drug, procedure, etc. causes improved outcomes in patients.
He then performs a hypothesis test using the following hypotheses:
H0: ?after = ?before (the mean blood pressure is the same before and after using the drug)
HA: ?after < ?before (the mean blood pressure is less after using the drug)
If the p-value of the test is less than some significance level (e.g. ? = .05), then he can reject the null hypothesis and conclude that the new drug leads to reduced blood pressure.
In Business
For example, suppose a company believes that spending more money on digital advertising leads to increased sales. To test this, the company may increase money spent on digital advertising during a two-month period and collect data to see if overall sales have increased.
H0: ?after = ?before (the mean sales is the same before and after spending more on advertising)
HA: ?after > ?before (the mean sales increased after spending more on advertising)
If the p-value of the test is less than some significance level (e.g. ? = .05), then the company can reject the null hypothesis and conclude that increased digital advertising leads to increased sales.
Hypothesis tests are also used often in manufacturing plants to determine if some new process, technique, method, etc. causes a change in the number of defective products produced.
For example, suppose a certain manufacturing plant wants to test whether or not some new method changes the number of defective widgets produced per month, which is currently 250. To test this, they may measure the mean number of defective widgets produced before and after using the new method for one month.
They can then perform a hypothesis test using the following hypotheses:
H0: ?after = ?before (the mean number of defective widgets is the same before and after using the new method)
HA: ?after ? ?before (the mean number of defective widgets produced is different before and after using the new method)
In classrooms
Step 1: State the
Null hypothesiLinks to an external site.
. The accepted fact is that the
population meaninks to an external site.
is 100, so: H0: ? = 100.
Step 2: State the
Alternate HypothesiLinks to an external site.
. The claim is that the students have above average IQ scores, so:H1: ? > 100.The fact that we are looking for scores “greater than” a certain point means that this is a
one-tailed test.inks to an external site.
