document.write( "Question 1179208: Hi! Please help with the following question! Thank you so much!\r
\n" ); document.write( "\n" ); document.write( " A coffee machine dispenses normally distributed amounts of coffee with a mean of 12 ounces and a standard deviation of 0.2 ounce. If a sample of 9 cups is selected, find the probability that the mean of the sample will be greater than 12.1 ounces.
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Algebra.Com's Answer #850259 by CPhill(1959)\"\" \"About 
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Here's how to solve this problem:\r
\n" ); document.write( "\n" ); document.write( "**1. Understand the Problem:**\r
\n" ); document.write( "\n" ); document.write( "* We're dealing with a normally distributed population (coffee dispensed) with a known mean and standard deviation.
\n" ); document.write( "* We're interested in the probability of a sample mean being greater than a certain value.
\n" ); document.write( "* This requires using the Central Limit Theorem and z-scores.\r
\n" ); document.write( "\n" ); document.write( "**2. Define the Parameters:**\r
\n" ); document.write( "\n" ); document.write( "* Population mean (μ): 12 ounces
\n" ); document.write( "* Population standard deviation (σ): 0.2 ounces
\n" ); document.write( "* Sample size (n): 9
\n" ); document.write( "* Sample mean (x̄): 12.1 ounces\r
\n" ); document.write( "\n" ); document.write( "**3. Calculate the Standard Error of the Mean:**\r
\n" ); document.write( "\n" ); document.write( "* The standard error (SE) is the standard deviation of the sampling distribution of the mean.
\n" ); document.write( "* SE = σ / √n = 0.2 / √9 = 0.2 / 3 ≈ 0.0667 ounces\r
\n" ); document.write( "\n" ); document.write( "**4. Calculate the Z-Score:**\r
\n" ); document.write( "\n" ); document.write( "* The z-score tells us how many standard errors the sample mean is away from the population mean.
\n" ); document.write( "* z = (x̄ - μ) / SE = (12.1 - 12) / 0.0667 = 0.1 / 0.0667 ≈ 1.5\r
\n" ); document.write( "\n" ); document.write( "**5. Find the Probability:**\r
\n" ); document.write( "\n" ); document.write( "* We want to find P(x̄ > 12.1), which is the same as P(z > 1.5).
\n" ); document.write( "* Using a z-table or calculator:
\n" ); document.write( " * P(z < 1.5) ≈ 0.9332
\n" ); document.write( " * P(z > 1.5) = 1 - P(z < 1.5) = 1 - 0.9332 ≈ 0.0668\r
\n" ); document.write( "\n" ); document.write( "**Answer:**\r
\n" ); document.write( "\n" ); document.write( "The probability that the mean of the sample will be greater than 12.1 ounces is approximately 0.0668.
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