By Consumer Dummies

When finding probabilities for a normal distribution (less than, greater than, or in between), you need to be able to write probability notations. Practice these skills by writing probability notations for the following problems.

Sample questions

  1. Write the probability notation for the area shaded in this Z-distribution.

    image0.png
    image1.jpg

    Answer:

    image2.png

    Looking at the graph, you see that the shaded area represents the probability of all z-values of 2 or less. The probability notation for this is

    image3.png

  2. Write the probability notation for the area shaded in this Z-distribution.

    image4.png
    image5.jpg

    Answer:

    image6.png

    Looking at the graph, you see that the shaded area represents the probability that Z is between 0 and 2, expressed as

    image7.png

  3. Write the probability notation for the area shaded in this Z-distribution.

    image8.png
    image9.jpg

    Answer:

    image10.png

    Looking at the graph, you see that the shaded area represents the probability of a z-value of –2 or higher, expressed as

    image11.png

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