document.write( "Question 1192318: 40% of the employees at a large corporation are female a sample of 50 employees is taken and gender is recorded what is the probability of sample proportion of females in sample between 0.35 and 0.45? \n" ); document.write( "
Algebra.Com's Answer #849048 by CPhill(1959)\"\" \"About 
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**1. Define Variables**\r
\n" ); document.write( "\n" ); document.write( "* **Population Proportion (p):** 0.40 (40% of employees are female)
\n" ); document.write( "* **Sample Size (n):** 50
\n" ); document.write( "* **Sample Proportion (p-hat):** Proportion of females in the sample\r
\n" ); document.write( "\n" ); document.write( "**2. Check Conditions for Normal Approximation**\r
\n" ); document.write( "\n" ); document.write( "* **Independence:** We assume that the employees are randomly selected and that the sample size is less than 10% of the total population.
\n" ); document.write( "* **Success-Failure Condition:**
\n" ); document.write( " * np = 0.40 * 50 = 20 (Number of female employees in the sample)
\n" ); document.write( " * n(1-p) = 50 * 0.60 = 30 (Number of male employees in the sample)
\n" ); document.write( " * Both np and n(1-p) are greater than 10, so the condition is met.\r
\n" ); document.write( "\n" ); document.write( "Since the conditions are met, we can use the normal approximation to the binomial distribution.\r
\n" ); document.write( "\n" ); document.write( "**3. Calculate Standard Error**\r
\n" ); document.write( "\n" ); document.write( "* Standard Error (SE) = √[p * (1-p) / n]
\n" ); document.write( "* SE = √[0.40 * 0.60 / 50]
\n" ); document.write( "* SE = √[0.24 / 50]
\n" ); document.write( "* SE = √0.0048
\n" ); document.write( "* SE ≈ 0.0693\r
\n" ); document.write( "\n" ); document.write( "**4. Standardize the Values**\r
\n" ); document.write( "\n" ); document.write( "* **For p-hat = 0.35:**
\n" ); document.write( " * z = (0.35 - 0.40) / 0.0693 ≈ -0.72
\n" ); document.write( "* **For p-hat = 0.45:**
\n" ); document.write( " * z = (0.45 - 0.40) / 0.0693 ≈ 0.72\r
\n" ); document.write( "\n" ); document.write( "**5. Find the Probability**\r
\n" ); document.write( "\n" ); document.write( "* We want to find P(0.35 < p-hat < 0.45)
\n" ); document.write( "* This is equivalent to finding P(-0.72 < z < 0.72)
\n" ); document.write( "* Using a standard normal table or calculator, we find:
\n" ); document.write( " * P(z < 0.72) ≈ 0.7642
\n" ); document.write( " * P(z < -0.72) ≈ 0.2358
\n" ); document.write( "* P(-0.72 < z < 0.72) = P(z < 0.72) - P(z < -0.72)
\n" ); document.write( "* P(-0.72 < z < 0.72) ≈ 0.7642 - 0.2358
\n" ); document.write( "* P(-0.72 < z < 0.72) ≈ 0.5284\r
\n" ); document.write( "\n" ); document.write( "**Therefore, the probability that the sample proportion of females in the sample is between 0.35 and 0.45 is approximately 0.5284.**
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