(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A drinks machine dispenses coffee into cups. A ign on the machine inicats that each cup contains 50ml of coffee. The machine actually dispenses a mean amount of 55 ml per cup and 10% of the cups contain less than the amount stated on the sign. Assuming that the amount of coffee is normally distributed find

a) the standard deviation of the amount of coffee dispensed per cup in ml.

2. Relevant equations

3. The attempt at a solution

Well Z ~ N(u,o°)

P(Z < 50) = 0.1

standardise this

[tex]P(Z < \frac{50-55}{o}) = 0.1[/tex]

So what do I do next. I thought look up the prob distrubution of z = 0.1 in the prob dist tables = 0.5398 but the mark scheme doesn't show this happening at all.

What should I do

Thanks :)

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Probality Question

**Physics Forums | Science Articles, Homework Help, Discussion**