Math Problem Statement

A political campaign is interested in whether city 1 has more support for raising the minimum wage than city 2. Polls were conducted in the two largest cities in the state about raising the minimum wage. In city 1, a poll of 800 randomly selected voters found that 518 supported raising the minimum wage. In city 2, a poll of 1000 randomly selected voters found that 611 supported raising the minimum wage.

What type of hypothesis test should be performed? (two-tailed z-test, right tailed z-test, tow tailed t-test, left tailed z-test) What type of hypothesis test should be performed?

p^1=

p^2=

p^=

Test statistic =

p-value Does sufficient evidence exist to support the claim that the level of support differs between the two cities at the α=0.01 significance level?yes or no?

Solution

To determine the type of hypothesis test and perform the necessary calculations, let's go step by step.


Type of Hypothesis Test

This is a two-tailed z-test because we are comparing the proportions of two independent groups (city 1 and city 2) to check if there is a significant difference between their support levels.


Step-by-Step Calculations

1. Sample Proportions:

p1=Number of supporters in City 1Sample size of City 1=518800=0.6475p_1 = \frac{\text{Number of supporters in City 1}}{\text{Sample size of City 1}} = \frac{518}{800} = 0.6475 p2=Number of supporters in City 2Sample size of City 2=6111000=0.611p_2 = \frac{\text{Number of supporters in City 2}}{\text{Sample size of City 2}} = \frac{611}{1000} = 0.611

2. Combined Proportion (pp^*):

p=Total supporters from both citiesTotal sample size from both cities=518+611800+1000=112918000.6272p^* = \frac{\text{Total supporters from both cities}}{\text{Total sample size from both cities}} = \frac{518 + 611}{800 + 1000} = \frac{1129}{1800} \approx 0.6272

3. Standard Error (SESE):

SE=p(1p)(1n1+1n2)=0.6272(10.6272)(1800+11000)SE = \sqrt{p^*(1 - p^*) \left( \frac{1}{n_1} + \frac{1}{n_2} \right)} = \sqrt{0.6272(1 - 0.6272) \left( \frac{1}{800} + \frac{1}{1000} \right)} SE0.62720.3728(0.00125+0.001)=0.62720.37280.002250.0005250.0229SE \approx \sqrt{0.6272 \cdot 0.3728 \cdot (0.00125 + 0.001)} = \sqrt{0.6272 \cdot 0.3728 \cdot 0.00225} \approx \sqrt{0.000525} \approx 0.0229

4. Test Statistic (zz):

z=p1p2SE=0.64750.6110.02290.03650.02291.59z = \frac{p_1 - p_2}{SE} = \frac{0.6475 - 0.611}{0.0229} \approx \frac{0.0365}{0.0229} \approx 1.59

5. p-value:

For a two-tailed test, we find the p-value corresponding to z=1.59z = 1.59: p-value=2P(Z>1.59)p\text{-value} = 2 \cdot P(Z > 1.59) Using a standard normal table or calculator: P(Z>1.59)0.0559P(Z > 1.59) \approx 0.0559 p-value=20.0559=0.1118p\text{-value} = 2 \cdot 0.0559 = 0.1118


Conclusion:

At a significance level of α=0.01\alpha = 0.01, the p-value (0.11180.1118) is greater than α\alpha.

Thus, we fail to reject the null hypothesis. There is insufficient evidence to support the claim that the level of support for raising the minimum wage differs between the two cities.


Final Answers:

  1. Type of hypothesis test: Two-tailed z-test
  2. p1=0.6475p_1 = 0.6475
  3. p2=0.611p_2 = 0.611
  4. p=0.6272p^* = 0.6272
  5. Test statistic: z1.59z \approx 1.59
  6. p-value: 0.11180.1118
  7. Conclusion: No, sufficient evidence does not exist at α=0.01\alpha = 0.01.

Do you want further clarification or additional examples?
Here are 5 related questions to expand on this:

  1. How would the test change if we used a one-tailed z-test?
  2. What sample sizes are needed to reduce the p-value below 0.01?
  3. How is the combined proportion pp^* used in hypothesis testing?
  4. How does the significance level affect the decision in hypothesis testing?
  5. What are the assumptions behind using a z-test for proportions?

Tip: Always check if the sample sizes are large enough for the z-test approximation to the normal distribution to be valid. A general rule is np>5np > 5 and n(1p)>5n(1-p) > 5.

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Math Problem Analysis

Mathematical Concepts

Hypothesis Testing
Proportions
Two-Tailed Tests
Significance Testing

Formulas

Sample proportion formula: p = x / n
Combined proportion formula: p* = (x1 + x2) / (n1 + n2)
Standard error for two proportions: SE = sqrt(p*(1 - p*) * (1/n1 + 1/n2))
Test statistic for proportions: z = (p1 - p2) / SE

Theorems

Central Limit Theorem
Normal Approximation for Proportions

Suitable Grade Level

Undergraduate Statistics or AP Statistics