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A group of students investigated the claim that baking a …

Mathematics Questions

A group of students investigated the claim that baking a fair die at 200¬¨‚àûF for 10 minutes alters its balance, leading to a higher probability of rolling a 6. After baking the die with the 6 face up and rolling it 200 times, they found that the number 6 landed face up 43 times. Clarke constructed a 95 percent confidence interval for the population proportion ( p ) as ( 0.215 pm 0.057 ). (a) Does the confidence interval provide convincing evidence that rolling a 6 occurs more frequently on the baked die than on a fair die? Explain your reasoning. (b) Aurelia conducted a significance test with hypotheses ( H_0: p = frac{1}{6} ) versus ( H_a: p > frac{1}{6} ) at a significance level of ( alpha = 0.05 ). With a test statistic of 1.83 and a p-value of 0.033, do the results agree with Clarke’s confidence interval in part (a)? Explain your reasoning. (c) Joachim suggested developing a one-sided confidence interval since they only needed to determine if the number 6 landed face up more often. He proposed using the formula for ( L ): ( L = hat{p} + z^*sqrt{hat{p}(1 – hat{p})/n} ). (i) Determine the value of ( z^* ) for a one-sided 95 percent confidence interval and calculate ( L ). (ii) Do Joachim’s one-sided confidence interval results align with Aurelia’s significance test results in part (b)? Explain your reasoning.

Short Answer

Clarke’s confidence interval for the probability of rolling a 6 suggests that the die may not be biased, as it includes the fair value of 1/6, indicating weak evidence of bias. In contrast, Aurelia’s significance test shows a p-value of 0.033, leading to the rejection of the null hypothesis and suggesting that the die does favor the number 6. Additionally, Joachim’s one-sided interval indicates that values for rolling a 6 are greater than 0.23, further supporting the conclusion of bias in favor of rolling a 6.

Step-by-Step Solution

Step 1: Understanding Clarke’s Confidence Interval

Clarke’s confidence interval for the proportion of rolling a 6 with the manipulated die is calculated as 0.215 ¬¨¬± 0.057. This interval ranges from 0.158 to 0.272 and includes the value of 1/6 (0.167), which indicates that the die may not be favoring the number 6 more than a fair die. Since this value is part of the interval, it implies there isn’t strong statistical evidence to claim the die is biased toward the number 6.

Step 2: Analyzing Aurelia’s Significance Test

Aurelia’s significance test results provide a complementary perspective, where the p-value is recorded at 0.033. This p-value is less than the significance level of 0.05, leading to the rejection of the null hypothesis. Hence, this suggests there exists statistically significant evidence that the number 6 appears more frequently on the baked die compared to a standard die.

Step 3: Exploring Joachim’s One-Sided Confidence Interval

Joachim’s analysis utilizes a one-sided confidence interval, with a critical value Z* of 1.645. This results in a lower limit (L) of approximately 0.23, indicating that all plausible values of p for rolling a 6 are greater than this threshold. Thus, Joachim’s findings support Aurelia’s conclusions, suggesting the number 6 is indeed rolled more often on the manipulated die.

Related Concepts

Confidence Interval

Defines a range of values that is likely to contain the true proportion of a population parameter, calculated from sample data

P-Value

The probability of obtaining a test statistic at least as extreme as the one observed, assuming the null hypothesis is true, used to determine statistical significance

Null Hypothesis

A statement asserting that there is no effect or no difference, which is tested and potentially rejected based on the data analysis.

Table Of Contents
  1. A group of students investigated the claim that baking a fair die at 200¬¨‚àûF for 10 minutes alters its balance, leading to a higher probability of rolling a 6. After baking the die with the 6 face up and rolling it 200 times, they found that the number 6 landed face up 43 times. Clarke constructed a 95 percent confidence interval for the population proportion ( p ) as ( 0.215 pm 0.057 ). (a) Does the confidence interval provide convincing evidence that rolling a 6 occurs more frequently on the baked die than on a fair die? Explain your reasoning. (b) Aurelia conducted a significance test with hypotheses ( H_0: p = frac{1}{6} ) versus ( H_a: p > frac{1}{6} ) at a significance level of ( alpha = 0.05 ). With a test statistic of 1.83 and a p-value of 0.033, do the results agree with Clarke's confidence interval in part (a)? Explain your reasoning. (c) Joachim suggested developing a one-sided confidence interval since they only needed to determine if the number 6 landed face up more often. He proposed using the formula for ( L ): ( L = hat{p} + z^*sqrt{hat{p}(1 – hat{p})/n} ). (i) Determine the value of ( z^* ) for a one-sided 95 percent confidence interval and calculate ( L ). (ii) Do Joachim's one-sided confidence interval results align with Aurelia's significance test results in part (b)? Explain your reasoning.