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4. the drama club believes that the proportion of students who bring in…

Question

  1. the drama club believes that the proportion of students who bring in holiday treats to share during the last week of school is different from 50%. (they arent sure if more students will bring treats... or if everyone will forget.) hypotheses: $h_0: p = 0.50$ $h_a: p \

eq 0.50$ evidence: a random sample of 160 students is taken, and 92 of them brought holiday treats. $\hat{p} = \square$ (unreduced fraction) unusualness: $z = \square$ (three decimal places) chances: p - value = $\square$ (three decimal places)

Explanation:

Step1: Calculate sample proportion

$\hat{p} = \frac{\text{Number of successes}}{\text{Sample size}} = \frac{92}{160}$

Step2: Simplify the fraction

Divide numerator and denominator by 4: $\frac{92\div4}{160\div4} = \frac{23}{40}$

Step3: Compute test statistic (z-score)

Formula: $z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0(1-p_0)}{n}}}$
Substitute values: $p_0=0.50$, $n=160$, $\hat{p}=0.575$
$z = \frac{0.575 - 0.50}{\sqrt{\frac{0.50\times0.50}{160}}} = \frac{0.075}{\sqrt{0.25/160}} = \frac{0.075}{\sqrt{0.0015625}} = \frac{0.075}{0.039528} \approx 1.897$

Step4: Find P-value for two-tailed test

Z=1.897 corresponds to one-tailed area ≈0.0289; two-tailed P-value=2×0.0289≈0.0578

Answer:

$\hat{p} = \frac{23}{40}$, z ≈ 1.897, P-value ≈ 0.058