Aresearcher finds that 15% of all commuters in a metropolitan area take the train to work. the researcher polls 250 people in the area and asks them whether they take the train to work. what is the number of trials for this binomial experiment?
15
38
250
265

250

Step-by-step explanation:

Binomial :

where n = no. of trials

           r = No. of success desired

          p = probability of getting success

          q = Probability of getting failure

Now we are given that  researcher finds that 15% of all commuters in a metropolitan area take the train to work.

So, p = 0.15

q = 1-p = 1-0.15

The researcher polls 250 people in the area

So, n = 250

So,  

So, n = 250

Since n denotes the number of trials .

So,  the number of trials for this binomial experiment is 250

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