Question

Sally has a bag of marbles. She chose a marble, recorded the color, and placed it back into the bag. She did this50 times. The table shows the results.ColorNumberPink124WhiteBlue15Purple9Green10Using the experimental probability that can be found in the table, if Sally was to repeat this experiment 600times, how many times can she expect to choose a blue marble?

Answer 1

Given an experimental probability sample of marble with different colours

Given the probability of an event formula as

$P(x)=\frac{n(x)}{n(T)}$

The probability that Sally will choose blue once will be

$\begin{gathered} P(B)=\frac{n(B)}{n(T)} \\ \text{Where } \\ n(B)=15,n(T)=50 \end{gathered}$$P(B)=\frac{15}{50}=\frac{3}{10}$

Thus, the number of times Sally choosing blue if the experiment was repeated 600 times will be

$\begin{gathered} P(B)\times600 \\ \Rightarrow\frac{3}{10}\times600 \\ \Rightarrow\frac{1800}{10}=180 \end{gathered}$

Hence, the number of times she expects to choose a blue marble is 180 times