Normal Distribution and Probability

What is the area under the curve to the left of z = 0.55 ?

• .2912

• .5500

• .9394

• .7088

What is the area under the curve between z = 0 and z = 1.45?

• .9265

• .4265

• .4500

• .5000

What shape is a normal distribution curve?

• Half curve

• Round curve

• Bell curve

• Square curve

According to the empirical rule, what percentage of data falls within 1 standard deviation? 

• 25%

• 68%

• 95%

• 99.7%

According to the empirical rule, how much of the data falls within 3 standard deviations? 

• 25%

• 68%

• 95%

• 99.7%

The center of the curve represents what value of a data set?

• μ

• δ

• Σ

• Ζ

What is the total area under the curve?

• 1
• .9998
• .997
• -3 < z < 3

Which gray area shows a probability closer to 0.5?

• 
• 
• 
• 

The normal probability distribution is completely described by its mean and ________.

• variance

• standard deviation

• range

• mean deviation

By standardizing a normal probability distribution, we can report the distance of a value from the mean in units of the __________ .

• median

• standard deviation

• variance

• mode