(d) A drinks machine dispenses coffee into cups. A sign on the machine indicates that each cup contains 100ml of coffee. The machine actually dispenses a mean amount of 105ml per cup and 10% of the cups contain less than the amount stated on the sign. Assuming that the amount of coffee dispenses into each cup is normally distributed, find the standard deviation of the amount of coffee dispensed per cup in ml.

The standard deviation of the amount of coffee dispensed per cup in ml is 3.91.

Step-by-step explanation:

Let the random variable X denote the amount of coffee dispensed by the machine.

It is provided that the random variable, X is normally distributed with mean, μ = 105 ml/cup and standard deviation, σ.

It is also provided that a sign on the machine indicates that each cup contains 100 ml of coffee.

And 10% of the cups contain less than the amount stated on the sign.

To compute the probabilities of a normally distributed random variable, first convert the raw score to a z-score,

This implies that:

P (X < 100) = 0.10

⇒ P (Z < z) = 0.10

The value of z for the above probability is, z = -1.28.

*Use a z-table

Compute the value of standard deviation as follows:

Thus, the standard deviation of the amount of coffee dispensed per cup in ml is 3.91.

to plot points   for x just start at the origin (middle) and go to the left however many times it say(if the number is a positive) if the number is a negative then go right however many times it says if it is 0 go nowhere

now keep you pencil there and go up however many times it says on y(if it is positive) if it is negative then go down however many times it says. if it says 0 go nowhere.

you have just plotted a point! now when you finish plotting all of them connect them with a ruler

plot each point as (-3, 7), (0,4), (3,1), (8,-4)   in the parenthesis on the left of the comma is x and the right is y.

he will have 300 because he is really broke and 300 is in his imangine

step-by-step explanation: he ehe heh step by the thy