Answer:
You ask seventh-graders leaving the cafeteria after lunch.
Step-by-step explanation:
Try and choose a sample with the student group that has nothing to do with what you're testing for. It will take a bit of "creative" thinking and guessing about the lives of students in each of these groups. We try to choose a good sample to get accurate or less-biased results.
<u>You ask seventh-graders entering a library on Friday night. </u>
Friday night, some students are quicker to leave school and start the weekend. The students who go to the library might be more studious and work can be done on the computer. Libraries also have computers available for people to use for gaming. <em>Your sample would have students who use the computer more.</em>
<u />
<u>You ask seventh-graders leaving a school basketball game. </u>
Students who watch a basketball game usually do so by choice. We could assume that these students spend most of their free time playing sports, which are not done on the computer. <em>Your sample would contain students who use a computer less.</em>
<u />
<u>You ask seventh-graders leaving the cafeteria after lunch. </u>
The cafeteria is usually filled with all or most of the students in the entire school. Every student would need to eat, so you will find all "types" of students here. <em>Your sample would contain all "types" of students.</em>
<u />
<u>You ask seventh-graders entering the computer lab.</u>
These students very obviously use a computer, given you go to a place filled with computers to survey them. <em>Your sample would mostly contain students who use a computer more.</em>
Answer:
B
Step-by-step explanation:
Answer:
0.7061 = 70.61% probability she will have her first crash within the first 30 races she runs this season
Step-by-step explanation:
For each race, there are only two possible outcomes. Either the person has a crash, or the person does not. The probability of having a crash during a race is independent of whether there was a crash in any other race. This means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
A certain performer has an independent .04 probability of a crash in each race.
This means that 
a) What is the probability she will have her first crash within the first 30 races she runs this season
This is:

When 
We have that:



0.7061 = 70.61% probability she will have her first crash within the first 30 races she runs this season
The greatest common factor of 19x7 AND 3x5 is: X5
hope this helps