One study claimed that 86 % of college students identify themselves as procrastinators. A professor believes that the claim regarding college students is too high. The professor conducts a simple random sample of 139 college students and finds that 110 of them identify themselves as procrastinators. Does this evidence support the professor's claim that fewer than 86% of college students are procrastinators? Use a 0.05 level of significance. Step 3 of 3: Draw a conclusion and interpret the decision.

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### Statistical Analysis of Procrastination Among College Students

#### Claim and Hypothesis
One study reported that **86%** of college students identify themselves as procrastinators. A professor challenges this claim, suspecting that the percentage might be lower. To test this hypothesis, the professor conducts a simple random sample consisting of **139 college students**, finding that **110** of them identify as procrastinators.

#### Objective
Determine whether the professor's sample supports the hypothesis that fewer than **86%** of college students are procrastinators, utilizing a **0.05 level of significance**.

#### Steps to Conduct the Hypothesis Test:

**Step 3 of 3: Draw a conclusion and interpret the decision.**

This step involves concluding if the sample evidence provides sufficient basis to reject the initial claim.

#### Conclusion Drawing and Interpretation:

1. **Estimate Population Proportion**: Calculate the sample proportion (p̂) of procrastinators:
   \[
   \hat{p} = \frac{110}{139} \approx 0.791
   \]

2. **Formulate Hypotheses**:
   - Null Hypothesis (H₀): \( p \geq 0.86 \)
   - Alternative Hypothesis (H₁): \( p < 0.86 \)

3. **Calculate Test Statistic**: Apply the z-test for proportion:
   \[
   z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0 (1 - p_0)}{n}}} = \frac{0.791 - 0.86}{\sqrt{\frac{0.86 \cdot (1 - 0.86)}{139}}}
   \]

4. **Determine Critical Value and p-value**:
   - Critical value for a one-tailed test at 0.05 significance: \( z_{0.05} \approx -1.645 \)
   - Compare calculated z-value with this critical value or calculate the p-value for z.

5. **Make a Decision**:
   - If z calculated > critical z, fail to reject H₀.
   - If z calculated < critical z, reject H₀.

6. **Interpret the Decision**:
   - Based on the above comparison, derive whether the evidence strongly counters or supports the professor's claim. A decision to reject H₀ would indicate evidence supporting that fewer
Transcribed Image Text:### Statistical Analysis of Procrastination Among College Students #### Claim and Hypothesis One study reported that **86%** of college students identify themselves as procrastinators. A professor challenges this claim, suspecting that the percentage might be lower. To test this hypothesis, the professor conducts a simple random sample consisting of **139 college students**, finding that **110** of them identify as procrastinators. #### Objective Determine whether the professor's sample supports the hypothesis that fewer than **86%** of college students are procrastinators, utilizing a **0.05 level of significance**. #### Steps to Conduct the Hypothesis Test: **Step 3 of 3: Draw a conclusion and interpret the decision.** This step involves concluding if the sample evidence provides sufficient basis to reject the initial claim. #### Conclusion Drawing and Interpretation: 1. **Estimate Population Proportion**: Calculate the sample proportion (p̂) of procrastinators: \[ \hat{p} = \frac{110}{139} \approx 0.791 \] 2. **Formulate Hypotheses**: - Null Hypothesis (H₀): \( p \geq 0.86 \) - Alternative Hypothesis (H₁): \( p < 0.86 \) 3. **Calculate Test Statistic**: Apply the z-test for proportion: \[ z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0 (1 - p_0)}{n}}} = \frac{0.791 - 0.86}{\sqrt{\frac{0.86 \cdot (1 - 0.86)}{139}}} \] 4. **Determine Critical Value and p-value**: - Critical value for a one-tailed test at 0.05 significance: \( z_{0.05} \approx -1.645 \) - Compare calculated z-value with this critical value or calculate the p-value for z. 5. **Make a Decision**: - If z calculated > critical z, fail to reject H₀. - If z calculated < critical z, reject H₀. 6. **Interpret the Decision**: - Based on the above comparison, derive whether the evidence strongly counters or supports the professor's claim. A decision to reject H₀ would indicate evidence supporting that fewer
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