The population mean annual salary for environmental compliance specialists is about ​$62,000. A random sample of 32 specialists is drawn from this population. What is the probability that the mean salary of the sample is less than ​$59,000​? Assume σ=​$6,200.

Respuesta :

Answer: 0.002718

Step-by-step explanation:

Given : The population mean annual salary for environmental compliance specialists is about ​$62,000.

i.e. [tex]\mu=62000[/tex]  

Sample size : n= 32

[tex]\sigma=6200[/tex]

Let x be the random variable that represents the annual salary for environmental compliance specialists.

Using formula [tex]z=\dfrac{x-\mu}{\dfrac{\sigma}{\sqrt{n}}}[/tex], the z-value corresponds to x= 59000 will be :

[tex]z=\dfrac{59000-62000}{\dfrac{6200}{\sqrt{32}}}\approx\dfrac{-3000}{\dfrac{6200}{5.6568}}=-2.73716129032\approx-2.78[/tex]

Now, by using the standard normal z-table , the probability that the mean salary of the sample is less than ​$59,000 :-

[tex]P(z<-2.78)=0.002718[/tex]

Hence, the probability that the mean salary of the sample is less than ​$59,000= 0.002718