A normal distribution is observed from the number of customers retained per company's locations for a certain pharmaceutial company. If the mean is 16 customers and the standard deviation is 2 customers, what is the probability that a randomly selected location, the company retained between 12 and 20 customers

P = 0.9544

Step-by-step explanation:

To find the probability that a randomly selected location, the company retained between 12 and 20 customers, we are going to standardize 12 and 20 using the following equation:

Where x is the value, m is the mean and s is the standard deviation, so in a standard normal distribution, 12 and 20 are equal to:

Now, the probability that  the company retained between 12 and 20 customers is equal to the probability that the z value is between -2 and 2 in a standard normal distribution. So, using the normal distribution table we have:

P(-2<z<2) = P(z<2) - P(z<-2) = 0.9772 - 0.0228 = 0.9544

Probability that a randomly selected location, the company retained between 12 and 20 customers is 0.9545.

Step-by-step explanation:

We are given that a normal distribution is observed from the number of customers retained per company's locations for a certain pharmaceutical company where the mean is 16 customers and the standard deviation is 2 customers.

Let X = number of customers retained per company's locations for a certain pharmaceutical company

So, X ~ N()

Now, the z score probability distribution is given by;

        Z = ~ N(0,1)

where, = population mean

            = standard deviation

So, probability that a randomly selected location, the company retained between 12 and 20 customers is given by = P(12 < X < 20)

P(12 < X < 20) = P(X < 20) - P(X 12)

 P(X < 20) = P( < ) = P(Z < 2) = 0.97725

P(X 12) = P( ) = P(Z -2) = 1 - P(Z < 2)

                                             = 1 - 0.97725 = 0.02275

Now, P(12 < X < 20) = 0.97725 - 0.02275 = 0.9545

Therefore, probability that a randomly selected location, the company retained between 12 and 20 customers is 0.9545.

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5