hypothesis testing. what is a hypothesis in statistics, a hypothesis is a claim or statement about a...
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Hypothesis Testing
What is a Hypothesis
• In statistics, a hypothesis is a claim or statement about a characteristic of a population.
• A Null Hypothesis, denoted Ho, is a statistical hypothesis that contains a statement of equality such as .
• The Alternative Hypothesis, denoted Haa, is the , is the
compliment of the null hypothesis. It is a statement compliment of the null hypothesis. It is a statement that must be true if that must be true if Ho is false and it contains a statement of inequality, such as .
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Testing the Hypothesis
• There are two basic approaches to testing a hypothesis.
1) p-value approach
2) critical value approach
• Similar to when we calculated confidence intervals, the formula used depends upon the characteristics of the sample. These formulas result in a test statistic which is then examined at a given significance level.
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Age of patients:The admissions office at Memorial Hospital recently stated that the mean age of its patients was 46 years, with a standard deviation of 20 years. A random sample of 120 ages was obtained from admissions office records in an attempt to disprove the claim. Is a sample mean of 44.2 years significantly smaller than the claimed 46 years at the = .10 level of significance?
Hamburger Fat Content:A restaurant claims that its hamburgers have no more than 10 grams of fat. You work for a nutritional health agency and are asked to test this claim. You find that a random sample of nine hamburgers has a mean fat content of 13.5 grams and a standard deviation of 5.8 grams. A = 0.10, do you have evidence to reject the restaurant’s claim?
Genetically Modified Foods: An environmentalist claims that more than 58% of British consumers want supermarkets to stop selling genetically modified foods. You want to test this claim. You find that in a sample of 100 randomly selected British consumers, 61% say that they want supermarkets to stop selling genetically modified foods. At = 0.10, can you support the environmentalist’s claim?