Offshore drilling, Part I

Offshore drilling, Part I#

A survey asked 826 randomly sampled registered voters in California “Do you support? Or do you oppose? Drilling for oil and natural gas off the Coast of California? Or do you not know enough to say?” Below is the distribution of responses, separated based on whether or not the respondent graduated from college.

College Grad

Yes

No

—————–

——————————

——————————

Support

156

126

Oppose

179

122

Do not know

99

144

—————–

——————————

—————————–

Total

434

392

Part 1#

What percent of college graduates in this sample do not know enough to have an opinion on drilling for oil and natural gas off the Coast of California?

Answer Section#

Enter in a numeric value

Part 2#

What percent of non-college graduates in this sample do not know enough to have an opinion on drilling for oil and natural gas off the Coast of California?

Answer Section#

Enter in a numeric value

Part 3#

Let \(p\_{CG}\) and \(p\_{NCG}\) represent the proportion of college graduates and non-college graduates who responded “do not know”. Formulate the null and alternative hypothesis.

Answer Section#

  • \(H_0: p_{CG} = p_{NCG}\), \(H_A: p_{CG} ≠ p_{NCG}\)

  • \(H_0: p_{CG} = p_{NCG}\), \(H_A: p_{CG} > p_{NCG}\)

  • \(H_0: p_{CG} = p_{NCG}\), \(H_A: p_{CG} < p_{NCG}\)

  • \(H_0: p_{CG} > p_{NCG}\), \(H_A: p_{CG} ≠ p_{NCG}\)

Part 4#

Is the independence condition being satisfied?

Answer Section#

  • Yes

  • No

Part 5#

Calculate the pooled proportion.

Answer Section#

Enter in a numeric value

Part 6#

Considering the pooled proportion, has the success-failure condition been satisfied?

Answer Section#

  • Yes

  • No

Part 7#

Calculate the test statistic.

Answer Section#

Enter in a numeric value

Part 8#

Determine the p-value from the calculated test statistic.

Answer Section#

Enter in a numeric value

Part 9#

Based on the p-value and a significance level of 0.05, state whether you will reject or fail to reject the null hypothesis and explain the conclusion.

Answer Section#

  • Since the p-value is very large, we reject \(H_0\). The data provide weak evidence that the proportion of college graduates who do not have an opinion on this issue is different than that of non-college graduates.

  • Since the p-value is very small, we accept \(H_0\). The data provide strong evidence that the proportion of college graduates who do not have an opinion on this issue is the same as that of non-college graduates.

  • Since the p-value is very small, we reject \(H_0\). The data provide strong evidence that the proportion of college graduates who do not have an opinion on this issue is different than that of non-college graduates.

  • Since the p-value > 0.05, we fail to reject \(H_0\). The data do not provide strong evidence that the proportion of college graduates who do not have an opinion on this issue is different from that of non-college graduates.

Attribution#

Problem is from the OpenIntro Statistics textbook, licensed under the CC-BY 4.0 license.
Image representing the Creative Commons 4.0 BY license.