IDENTIFYING REGION

What does the total area under the normal curve represent?

• The variance of the data

• The total probability, which is equal to 1

• The range of the data

• The mode of the distribution

Which region under the normal curve represents the probability of a value being less than a given z-score?

• Right tail
  

• Left tail
  

• Between two z-scores
  

• • Entire curve

What is the probability of a value falling within one standard deviation from the mean in a normal distribution?

• A. 50%
  

• B. 68%
  

• C. 95%
  

• • D. 99.7%

Which of the following represents the area under the normal curve for the standard normal distribution between z=−1z = -1z=−1 and z=1z = 1z=1?

• A. 50%
  

• B. 68%
  

• C. 95%
  

• • D. 99.7%

If a z-score is negative, where is the corresponding area located under the normal curve?

• A. To the right of the mean
  

• B. To the left of the mean
  

• C. At the center
  

• • D. On both sides of the mean

What percentage of the area under the normal curve lies beyond two standard deviations from the mean?

• A. 5%
  

• B. 2.5%
  

• C. 0.15%
  

• • D. 1%

Which of the following describes the region corresponding to P(Z>1.96)P(Z > 1.96)P(Z>1.96) in a standard normal distribution?

• The area to the right of z=1.96z = 1.96z=1.96

• The area to the left of z=1.96z = 1.96z=1.96

• The total area under the curve

• The area between z=−1.96z = -1.96z=−1.96 and z=1.96z = 1.96z=1.96

What is the area under the normal curve between z=−2z = -2z=−2 and z=2z = 2z=2?

• A. 95%
  

• B. 68%
  

• C. 99.7%
  

• • D. 50%

What is the area under the normal curve outside the interval z=−3z = -3z=−3 to z=3z = 3z=3?

• A. 99.7%
  

• B. 0.3%
  

• C. 95%
  

• • D. 68%

Which of the following statements is true about the normal curve?

• A. It is always skewed to the right.
  

• B. The mean, median, and mode are all equal.
  

• C. The total area under the curve is greater than 1.
  

• 1. D. The probability of any exact z-score is always greater than 0.D. The probability of any exact z-score is always greater than 0.