document.write( "Question 1178054: two-tailed
\n" ); document.write( "right-tailed\r
\n" ); document.write( "\n" ); document.write( "Based on a sample of 40 men, 40% owned cats
\n" ); document.write( "Based on a sample of 40 women, 60% owned cats The test statistic is: Correct (to 2 decimals) The critical value is: (to 2 decimals) Based on this we:
\n" ); document.write( "Reject the null hypothesis
\n" ); document.write( "Fail to reject the null hypothesis
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #850371 by CPhill(1987)\"\" \"About 
You can put this solution on YOUR website!
Let's break down this problem step-by-step.\r
\n" ); document.write( "\n" ); document.write( "**1. Define the Variables**\r
\n" ); document.write( "\n" ); document.write( "* **p1:** Proportion of men who own cats (sample proportion p̂1 = 0.40)
\n" ); document.write( "* **p2:** Proportion of women who own cats (sample proportion p̂2 = 0.60)
\n" ); document.write( "* **n1:** Sample size of men (n1 = 40)
\n" ); document.write( "* **n2:** Sample size of women (n2 = 40)\r
\n" ); document.write( "\n" ); document.write( "**2. State the Hypotheses**\r
\n" ); document.write( "\n" ); document.write( "* **Null Hypothesis (H0):** p1 = p2 (There is no difference in the proportion of men and women who own cats)
\n" ); document.write( "* **Alternative Hypothesis (H1):** p1 ≠ p2 (There is a difference in the proportion of men and women who own cats)\r
\n" ); document.write( "\n" ); document.write( "Since the alternative hypothesis is \"not equal to,\" this is a **two-tailed** test.\r
\n" ); document.write( "\n" ); document.write( "**3. Calculate the Test Statistic (z-score)**\r
\n" ); document.write( "\n" ); document.write( "* **Pooled Proportion (p̂):**
\n" ); document.write( " * p̂ = (x1 + x2) / (n1 + n2) = (n1 * p̂1 + n2 * p̂2) / (n1 + n2)
\n" ); document.write( " * p̂ = (40 * 0.40 + 40 * 0.60) / (40 + 40) = (16 + 24) / 80 = 40 / 80 = 0.50
\n" ); document.write( "* **Standard Error (SE):**
\n" ); document.write( " * SE = √[p̂(1 - p̂) * (1/n1 + 1/n2)]
\n" ); document.write( " * SE = √[0.50 * 0.50 * (1/40 + 1/40)] = √[0.25 * (2/40)] = √[0.25 * 0.05] = √0.0125 ≈ 0.1118
\n" ); document.write( "* **Test Statistic (z):**
\n" ); document.write( " * z = (p̂1 - p̂2) / SE
\n" ); document.write( " * z = (0.40 - 0.60) / 0.1118 = -0.20 / 0.1118 ≈ -1.789\r
\n" ); document.write( "\n" ); document.write( "Rounded to two decimal places, the test statistic is **-1.79**.\r
\n" ); document.write( "\n" ); document.write( "**4. Determine the Critical Value**\r
\n" ); document.write( "\n" ); document.write( "* **Significance Level (α):** We need a significance level to determine the critical value. Let's assume a common significance level of α = 0.05.
\n" ); document.write( "* **Two-Tailed Test:** For a two-tailed test with α = 0.05, the critical values are ±z(α/2) = ±z(0.025).
\n" ); document.write( "* **Critical Value:** From the standard normal distribution table, z(0.025) ≈ 1.96. Therefore, the critical values are ±1.96.\r
\n" ); document.write( "\n" ); document.write( "**5. Make a Decision**\r
\n" ); document.write( "\n" ); document.write( "* **Compare Test Statistic and Critical Value:**
\n" ); document.write( " * The test statistic (-1.79) is within the range of the critical values (-1.96 and 1.96).
\n" ); document.write( " * |-1.79| < 1.96\r
\n" ); document.write( "\n" ); document.write( "* **Decision:** Since the test statistic is not in the rejection region, we **fail to reject the null hypothesis**.\r
\n" ); document.write( "\n" ); document.write( "**Answers**\r
\n" ); document.write( "\n" ); document.write( "* **Two-tailed**
\n" ); document.write( "* **Test statistic:** -1.79
\n" ); document.write( "* **Critical value:** 1.96
\n" ); document.write( "* **Based on this we:** Fail to reject the null hypothesis.
\n" ); document.write( "
\n" ); document.write( "
\n" );