A WBC count control has a mean value of 6000 / mL and a standard deviation of 300 / mL. What is the 95.5% confidence interval?

To calculate the 95.5% confidence interval for the WBC count control with a mean of 6000 / mL and a standard deviation of 300 / mL, we use the properties of a normal distribution. The confidence interval can be determined using the formula:

[ \text{Mean} \pm z \times \text{Standard Deviation} ]

For a 95.5% confidence level, the z-value is approximately 2. This means we will calculate the interval as follows:

1. Calculate the margin of error:

[ 2 \times 300 , \text{(standard deviation)} = 600 ]

2. Now, we find the confidence interval:

[

\text{Lower limit} = 6000 - 600 = 5400 , / \text{mL}

]

[

\text{Upper limit} = 6000 + 600 = 6600 , / \text{mL}

]

This results in a 95.5% confidence interval of 5400 / mL to 6600 / mL. This interval indicates that we are moderately confident that the true mean