Use the formula for the area of a circle to solve for the radius of the circle if the area is 78.5cm^2

Area = PI * radius^2

radius = Sq Root (Area / PI)

radius = Sq Root (78.5 / PI)

radius = Sq Root (24.9873260654)

radius = 4.9987

radius = 5 (rounded)

Step-by-step explanation:

The function that would correctly calculate the 90% range of likely sample means is given by:

B. 4,200±CONFIDENCE.T(0.10,140,12)

Step-by-step explanation:

In Microsoft Excel, the syntax

 returns the confidence  interval for the population mean, using the students T-distribution.

The standard deviation is given as $140 and the sample size is 12.

In constructing the confidence  interval we use:

Let us substitute the values to get:

We use the T distribution because is unknown