Q4-Learning Activity 5-STPB

According to Environmental Protection Agency (EPA) regulations, soil in play areas should not contain more than 400 parts per million (ppm) lead. Before starting construction on a new site, an agent will collect a sample of soil and conduct a significance test on the mean lead level in the soil. If the average lead level in the sample is much higher than 400ppm, the soil is considered unsafe, and construction cannot continue. The hypotheses to be tested are shown on the image.

What would be the consequence of a Type II error in this setting?

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Donated blood is screened for infectious diseases and other contaminants. Because most donated blood is safe, testing batches of donated blood saves time and money over testing individual samples. A test is performed to determine whether a specific toxin is present, and if it is found, the entire batch is rejected. This is comparable to utilizing a null and alternative hypothesis to decide whether to discard or maintain the batch. The hypotheses being tested are shown in the image.

What would be the consequence of a Type I error in this context?

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A recent nationwide poll reported a 9% unemployment rate in the US. The mayor of a nearby town wonders if this national statistic holds true for her town, so she intends to survey a sample of her inhabitants to discover if the unemployment rate differs considerably from 9%.
Let p be the unemployment rate in her town. The picture depicts the hypotheses she plans to test.

Which of the following would be a Type II error in this setting?

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It is a test that is utilized if the alternative hypothesis claims that one measure is greater than the other.

• right-tailed test

• left-tailed test

• two-tailed test

• t-test or z-test distribution

It is a measure in decision-making computed from the sample data.

• test statistic

• interval estimate

• point estimate

• statistical test of hypotheses

It is a method administered to decide whether or not to reject a hypothesis

• statistical test of hypotheses

• test statistic

• confidence interval estimate

• point estimate

The probability of rejecting the null hypothesis when in fact it is true.

• confidence level

• level of significance

• confidence coefficient

• standard deviation

This test is used when an alternative hypothesis is directional.

• t-test or z-test

• one-tailed test

• two-tailed test

• none of the options

It is a claim or a prediction concerning a relation or a variable.

• argument

• article

• hypothesis

• literature

Fill in the blanks.

There are two various forms of hypothesis. The _______________ states that there is no difference, no effect, or that nothing happened. The _______________ is a declaration that something occurred or had an effect.

• Null Hypothesis, Alternative Hypothesis

• Alternative Hypothesis, Null Hypothesis

• one-tailed test, two-tailed test

• two-tailed test, one-tailed test