Find the value of z* for a 90% confidence interval.

In a survey of 104 students, it was found that 79 went to the homecoming game this year.

A 99% confidence interval for p is (0.652, 0.868). Interpret this interval.

Find the critical value, z*, for 91% confidence.

Which confidence would result in a wider interval (assuming nothing else changed), 91% or 97%?

Which confidence would result in a wider interval (assuming nothing else changed), 91% or 97%?

For a sample, the 95% confidence interval is (0.202, 0.482).

What is the point estimate, p̂, of this sample?

For a sample, the 95% confidence interval is (0.202, 0.482).

What is the margin of error of this sample?

Which of the following actions would produce a confidence interval with a smaller width assuming all other contingencies remained constant?

Identify the correct null hypothesis:

Is the proportion of babies born male different from 50%? In a sample of 200 babies, 96 were male. Test the claim using a level of significance of 1%.

When p-value is greater than alpha we:

Suppose the P-value for a hypothesis test is 0.0304. Using a = 0.05, what is the appropriate conclusion?

A mayor is concerned about the percentage of city residents who express disapproval of his job performance. His political committee pays for a newspaper ad, hoping to keep his disapproval rating below 21%. They will use a follow up poll to access effectiveness. What are the correct null and alternative hypotheses?

Sally reads a newspaper report claiming that 12% of all adults in the U.S. are left-handed. She decides to test this claim. Sally selects a random sample of 55 classmates and finds that 9 were left-handed. Does this provide sufficient evidence that the proportion of lefties in Sally’s school is different than the national figure? Use α = 0.01.

Which is the correct p-value for this test?

A manufacturer has a set limit that the proportion of defective items is not to be over 18%. The buyer thinks the proportions of defective items exceeds the limit. The buyer take a random sample of 90 items and finds that 19 of them are defective.   The p-value is:

The symbol for the significance level is ____.

In hypothesis testing, if the p-value is less than the significance level, what is the appropriate decision?

The percentage of female CEOs in a group of companies was 5%. A survey of 300 randomly selected large companies said that 18 of them had female CEOs. Use a hypothesis test to determine whether the population proportion of female CEOs is not .05, using a significance level of .05. Determine if we accept or reject the null hypotheses and state the conclusion.