Evan is doing research, and he estimated the population mean using four random samples. Evan accidently erased one of the sample means. What is the missing sample mean if the estimated population mean is 14.1 and the sample means are 14.8, 13.2, 14.6?(1 point)

1 answer

To find the missing sample mean, we can use the formula for the estimated population mean, which is the average of the sample means.

Let the missing sample mean be \( x \). The formula for the population mean is:

\[ \text{Population Mean} = \frac{\text{Sum of sample means}}{\text{Number of samples}} \]

We know the estimated population mean is 14.1 and there are four samples. Therefore, we can write:

\[ 14.1 = \frac{14.8 + 13.2 + 14.6 + x}{4} \]

Now, let's calculate the sum of the known sample means:

\[ 14.8 + 13.2 + 14.6 = 42.6 \]

Now, substitute this into the equation:

\[ 14.1 = \frac{42.6 + x}{4} \]

To eliminate the fraction, multiply both sides by 4:

\[ 4 \times 14.1 = 42.6 + x \]

Calculating \( 4 \times 14.1 \):

\[ 56.4 = 42.6 + x \]

Now, isolate \( x \) by subtracting 42.6 from both sides:

\[ x = 56.4 - 42.6 \] \[ x = 13.8 \]

Thus, the missing sample mean is \( \boxed{13.8} \).