Arithmetic mean and standard deviation

Question

Answer 1

The arithmetic mean of multiple voltage measurements is .

The standard deviation is .

Let the random variable be multiple voltage measurements of the experiment.

Find the probability of measurements is above , .

Calculate the Z-score for the given probability.

,

Where is the number of voltage measurements.

is the mean and is the standard deviation.

For , Z-score is

From the Z-score table, Area of the region when is 0.8413.

Percentage of voltage measurements above the is .