Algebra 1 : Statistics and Probability

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #21 : Statistics And Probability

A student is interested in knowing how much time his classmates spend watching TV each night. He asks them and gets the following results (in minutes).

30, 60, 45, 42, 48, 87, 15, 22, 25, 92, 70, 75

What was the mean time spent watching TV?

Possible Answers:

Correct answer:

Explanation:

30, 60, 45, 42, 48, 87, 15, 22, 25, 92, 70, 75

First, sum the number of minutes spent watching TV by all classmates.

Then, divide the sum by the number of students. There are twelve values, so twelve students answered the question.

Example Question #21 : Statistics And Probability

A short quiz with 5 questions is given to a class of 30 students. 7 students answered 5 questions correctly, 12 students answered 4 questions correctly, 9 students answered 3 questions correctly, and 2 students answered 2 questions correctly.

What is the mean number of correct answers among the students in the class?

Possible Answers:

Correct answer:

Explanation:

To find the average score of the class, you must add the total score of all of the students and divide it by the number of students. 7 students answered 5 questions correctly, 12 students answered 4 questions correctly, 9 students answered 3 questions correctly, and 2 students answered 2 questions correctly, so this gives you a total score of 114: . Then, divide the total score of 114 by 30 to get an average score of 3.8

Example Question #11 : Basic Statistics

Find the mean of the following set of numbers: 32, 23, 46, 52, 37. 

Possible Answers:

Correct answer:

Explanation:

To find the mean, or average, of a set of numbers, you first add all of the numbers together:

.

Then, you divide the sum by the total number of numbers, which in this set is 5 (i.e., there are 5 numbers in this set):

.

38 is the mean, or average, of this set of numbers.

Example Question #21 : Statistics And Probability

Find the mean of the following: 65, 70, 91, 85, 89

Possible Answers:

Correct answer:

Explanation:

Example Question #21 : Statistics And Probability

We want to create a three-digit code for a combination lock.  Only digits from 0-9 are allowed and digits cannot be repeated.  How many such codes can be generated?

Possible Answers:

Correct answer:

Explanation:

The first position can be filled in 10 ways.  Since repetition is not allowed, the second position can be filled in 9 ways, and finally the third position can be filled in 8 ways giving us the correct answer of

Example Question #1451 : Algebra 1

We want to create a three-digit code for a combination lock.  Only digits from 0-9 are allowed and digits cannot be repeated.  Also a code can not start with 0.  How many such codes can be generated?

Possible Answers:

Correct answer:

Explanation:

The first position can be filled in 9 ways since 0 is not allowed.  In the second position 0 is allowed, less the digit placed in the first position, which gives us 9.  Hence the second position can be filled in 9 ways and as before the third position can be filled in only 8 ways which gives us the correct answer of

Example Question #27 : How To Find Mean

Evaluate:

Possible Answers:

Correct answer:

Explanation:

Hence,

 

Example Question #28 : How To Find Mean

Five contestants are competing for the following executive positions, namely,

President, Vice President, and Secretary.

 

How many ways the executive positions can be filled ?

Possible Answers:

Correct answer:

Explanation:

This is a permutation problem and here the order is important.  The correct way to answer this question is to calculate

which equals to

which is 60.

Example Question #21 : Statistics And Probability

If you toss 3 fair coins what is the sample space? (Tossing a coin results in either a Head "H" or a Tail "T")

Possible Answers:

Correct answer:

Explanation:

When you toss a coin, there are two outcomes. Hence when you toss 3 coins the total number of outcomes will be 8 and the sample space is given by:

 

Example Question #21 : Statistics And Probability

If we toss two dice, what is the probability of rolling doubles?

Possible Answers:

Correct answer:

Explanation:

A double consists of the following set . There are thus 6 possibilities out of 36 total outcomes.

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