Given IQ~N(100, 256) find P(IQ > 115).
Be certain to set your calculator to FLOAT 4 to match my answer exactly.
I need to know how to figure this out on my calculator.... no one has taught me how to use my calc and I am so confused.... someone please help!
To find P(IQ > 115) for the given normal distribution IQ ~ N(100, 256), you can use the cumulative distribution function (CDF) on your calculator.
Here's how you can do it on most calculators:
Step 1: Go to the distribution menu.
- Look for a menu that includes statistical distributions.
- On some calculators, you may need to access the catalog or press a specific key combination to get to the distribution menu.
Step 2: Select the normal distribution.
- Look for the normal distribution or "N" in the menu options.
- Some calculators may have multiple options for the normal distribution, such as "normalcdf" or "normcdf".
Step 3: Enter the parameters of the distribution.
- Enter the mean, 100, as the first parameter.
- Enter the standard deviation, which is the square root of the variance given as 256, so the standard deviation is 16.
Step 4: Specify the range of the random variable.
- Enter the lower bound, 115, as the second parameter.
- Since you want to find P(IQ > 115), you need to specify the upper bound as a very large number to ensure that it approaches infinity. On calculators, you can typically use a very large value such as 1E99 or "inf" to represent infinity.
Step 5: Calculate the probability.
- Press the calculate or enter button to find the probability.
- Make sure your calculator is set to display the result with the desired level of precision (FLOAT 4 in this case).
The resulting value should represent the probability P(IQ > 115) for the given normal distribution.