Determine the probability that a random variable

AI Thread Summary
To determine the probability that a normally distributed random variable (X) with a mean (μ) of 20.15 and a standard deviation (σ) of 6.27 takes on a value less than 9.5, the standardized score (z-score) is calculated as -1.698. Users can find the probability using statistical software or calculators, specifically through the normal cumulative distribution function (normal CD). For the Casio ClassPad, the process involves accessing the stats program, selecting the distribution option, and inputting the lower value as negative infinity. The discussion highlights the importance of using the correct tools for statistical calculations. Overall, the conversation emphasizes practical methods for calculating probabilities in statistics.
Sirsh
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Hello my question is stated below:

Task 3: Determine the probability that a random variable (X) having a normal distribution with μ = 20.15 and σ = 6.27 minutes will take on a value less than 9.5.

I've tried this:

Standardised score = (9.6-20.15)/6.27 = -1.698

Now i don't know how to find the pribability of this score on a stats sheet or using my casio classpad. does anyone else know how to do this?

Thank you.
 
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to do it on your casio classpad you can use the stats program. click on the calc dropdown, all the way at the bottom is distribution, click on that then you want to use normal CD, click next and use your lower value as -infinity then you should be able to figure the rest.
 


Pretty much finished the assignment before you replied lmao.
 
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