Algebra 1 : Statistics and Probability

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #11 : Statistics And Probability

Hours_chart

The above chart shows a specific week of work at an advertising firm.  What is the mean hourly rate of the female staff members?

Possible Answers:

Correct answer:

Explanation:

 

Example Question #11 : Statistics And Probability

The average score on a math exam for 5 students is 90. If the sixth student earned a score of 84, what is the average score for all 6 students?

Possible Answers:

None of the other answers

Correct answer:

Explanation:

The average of the first 5 students' scores is 90, which means that the total score for these 5 students is 450. To find the total score of all 6 students, you simply add the sixth student's score of 84 to the first 5 students' total score of 450, which gives you a total score of 534 for all 6 students. To determine the average score, you must divide the total score of 534 by 6, which gives you an average score of 89.

Example Question #13 : Statistics And Probability

Abe, George, and Tom took an algebra test last week and scored an average of 90. If Abe earned a score of 92 and George earned a score of 94, what was Tom's score on the test?

Possible Answers:

Correct answer:

Explanation:

Since they had an average score of 90, we know that their total score must have been 270 (90 multiplied by 3). We know that 2 of the scores are 94 and 92, so the third score must be , which is 84.

Example Question #1 : Basic Statistics

The mean of the set  is 20. What is the mean of the set ?

Possible Answers:

Correct answer:

Explanation:

To find mean, we add up the values in a set and divide by the number of terms in that set. We begin this problem with the knowledge that the mean of the first set is 20. Since that set contains five numbers, we know that its total sum must be 100 (since 100 divided by 5 is 20).

 

so  must be 25.

Now, the only step left is to find the mean of .

These values add up to 125, and when we divide by 5, we are left with a final answer of 25.

Example Question #11 : Statistics And Probability

If , what is the mean of the set ?

Possible Answers:

Correct answer:

Explanation:

If we substitute 3 in for , we find that our original set is equal to . To find the mean, add the values and divide by the number of terms in the set (in this case, 5). Here, the sum of the values is 35. Dividing by 5 yields a final answer of 7 for our mean.

Example Question #1441 : Algebra 1

A math test was given to a classroom of students last week. 8 students received a score of 90, 6 students received a score of 80, and 6 students received a score of 70. What was the average score of the class?

Possible Answers:

Correct answer:

Explanation:

To find the average score, you must total the scores of everyone in the class and divide it by the number of students in the class. 8 students received a score of 90, 6 students received a score of 80, and 6 students received a score of 70. The total score of the class is . There are 20 students in the class, so the average score must be .

Example Question #17 : Statistics And Probability

This semester, Reese took 4 tests for his algebra class. Among the 4 tests, he earned an average score of 88. If he scored an 84, 85, and 90 on his first 3 tests, what was his score on the fourth test?

Possible Answers:

Correct answer:

Explanation:

Reese's average score is calculated by dividing the sum of his test scores by the number of tests he took. This semester, Reese took 4 tests and his average score was 88, which means the sum of his test scores must be 362 (88 multiplied by 4). On the first three tests, he scored an 84, 85, and 90. This means that his fourth test score must be

Example Question #11 : How To Find Mean

In terms of , give the mean of these five data values:

Possible Answers:

Correct answer:

Explanation:

Add, then divide by 5:

Example Question #19 : Statistics And Probability

What is the mean of all of the prime numbers between 75 and 100?

Possible Answers:

Correct answer:

Explanation:

The prime numbers between 75 and 100 are 79, 83, 89, and 97. To find their mean, add them and divide by 4:

Example Question #11 : Statistics And Probability

What is the mean of all of the natural numbers from 1 to 99?

Possible Answers:

Correct answer:

Explanation:

The sum of the first  natural numbers is , so their mean is  

The mean of the first 99 natural numbers is .

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