jamila has a fair six - sided number cube with faces numbered 1 - 6. she rolls the number cube 60 times. how…
jamila has a fair six - sided number cube with faces numbered 1 - 6. she rolls the number cube 60 times. how many times should she expect to roll a number greater than 4?
Answer
Explanation:
Step1: Calculate probability of rolling > 4
The numbers greater than 4 on a 1 - 6 number cube are 5 and 6. So there are 2 favorable outcomes out of 6 total outcomes. The probability $P$ of rolling a number greater than 4 is $P=\frac{2}{6}=\frac{1}{3}$.
Step2: Calculate expected number of rolls
The expected value $E$ of the number of times to roll a number greater than 4 in 60 rolls is given by $E = n\times P$, where $n = 60$ (number of trials) and $P=\frac{1}{3}$. So $E=60\times\frac{1}{3}=20$.
Answer:
20