This discussion introduces you to normal probability via the calculated z-score. A z-score converts a nonstandard normal distribution into a standard normal distribution; a standard normal distribution has a mean
of zero and standard deviation of one.
Additional z-score properties and details are provided later in the course. For this assignment, what is
needed is the capability to calculate a z-score and find its associated probability (see Table A-2 in your
textbook). Here is an example:
Excel equation: z = (Your Score (X) – Mean)/(Standard Deviation) OR z = (X – Mean)/S.
Z-score and probability calculation example:
Assume Intelligent Quotient (IQ) scores are normally distributed with a Mean of 100 and Standard
Deviation of 15.
Assume a friend has an IQ score of 130 (X).
The z-score is then calculated: z = (130 – 100)/15 = 30/15 = 2.00.
Find Table A-2 in your textbook. The probability (green shaded area) associated with z = 2.00 is p =
The probability of another friend scoring “higher” (non-shaded area) than 130 is: p = (1.0000 – 0.9772) =
0.0228 or 2.28%.
Day 2 of the airshow arrives, and the weather is worsening. The temperature is 50oF, and strong
thunderstorms are predicted. Continuing intermittent moderate to strong runway crosswinds (25 Knots
sustained, with gusts to 40 Knots). Fortunately, all Day 2 flying sorties are accomplished with only minor
Your team collected these simulated data for Day 2 flying sorties:
In Microsoft Excel, complete the “Airshow – US Military Aircraft Performance” table by adding the
calculated column and row values for mean, standard deviation, and z-score column values (use Sortie 10
data as the value of “X” in the z-score equation); report your calculated values to two decimal places (i.e.,
0.12). For reporting probability, use Table A-2 in your textbook and report the value of p to four decimal
places (i.e., 0.1234).
Save your work as a file to your computer and then read the Canvas instructions on How do I embed an
image in a discussion reply as a student? (Links to an external site.)
Post & Discuss
Post the image of your spreadsheet into the discussion area along with a narrative of your findings before
the fourth day of the module week to receive full credit. Return at least once later in the module week to
provide meaningful comments to two or more of your classmates’ posts. DO NOT “post and run” – making
all three posts in the same visit. You need multiple visits to the discussion area to gain multiple
perspectives by reading all of the posts and replies.