I can't seem to get the correct answer for the homework question below. I am down to my last allowed submission attempt. I was hoping someone could...

I can't seem to get the correct answer for the homework question below. I am down to my last allowed submission attempt... I was hoping someone could explain how they would answer it. I came up with .2389 which is incorrect. Thank you.

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Let x be a random variable that represents white blood cell count per cubic milliliter of whole blood. Assume that x has a distribution that is approximately normal, with mean μ = 8300 and estimated standard deviation σ = 2800. A test result of x < 3500 is an indication of leukopenia. This indicates bone marrow depression that may be the result of a viral infection.

(a) What is the probability that, on a single test, x is less than 3500? (Round your answer to four decimal places.)