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A made-up survey of a large school gives this model for how a student comes to school: walk 0.32…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A made-up survey of a large school gives this model for how a student comes to school: walk , bus , cycle , and car, which is the only other way. Find the probability of car. A student is picked at random. Find the probability that the student walks or cycles. The school has students. About how many come by car?
Need a reminder? The key ideaShow
A relative frequency is the number of times an event happened divided by the number of tries. With equally likely outcomes, is the number of outcomes in divided by all outcomes. The probabilities of all the outcomes add up to .
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Car. .
Step 2. Walk or cycle. These cannot happen together, so add: .
Step 3. The count. students.
Answer: , and about students.
Watch out. The model comes from a survey, so it is an estimate. The real number of car students may be a little different from .
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