Afirm’s marketing manager believes that total sales X can be modeled using a normal distribution with mean m ¼ $2.5 million and standard deviation s ¼ $300,000. What is the probability that the firm’s sales will exceed $3 million?

Respuesta :

Answer: 0.0475

Step-by-step explanation:

Given :  A firm’s marketing manager believes that total sales X can be modeled using a normal distribution.

Where , Population mean : [tex]\mu=2.5\text{ million}=2.5\times1000000=2500000[/tex]

Standard deviation : [tex]\sigma=300000[/tex]

To find : Probability that the firm’s sales will exceed $3 million i.e. $ 3,000,000.

∵ [tex]z=\dfrac{x-\mu}{\sigma}[/tex]

Then , for x= 3,000,000

[tex]z=\dfrac{3000000-2500000}{300000}=1.67[/tex]

Then , the  probability that the firm’s sales will exceed $3 million is given by :-

[tex]P(z>1.67)=1-P(z<1.67)\\\\=1-0.9525403=0.0474597\approx0.0475[/tex]

Hence, the probability that the firm’s sales will exceed $3 million = 0.0475