Choose the number that is composite.

A. 2
B. 21
C. 31
D. 17

Answers

Answer 1

Answer: A composite number has more than two factors. (B) 21 is a composite number because the factors of 21 are 7 × 3.

Conditional frequencies offer more specific information to analyse certain data set.

Step-by-step explanation:

A conditional frequency is a type of relative frequency which involves a condition to be defined.

For example, the conditional frequency of having a house given that the person is female. Notice that this example shows the condition "being female", so the conditional frequency would be all females who own a house.

On the other hand, the relative frequency is just a ratio between the frequency of the data and the total number of data. It's doesn't includes a condition to be defined, that's the difference.

Therefore, conditional frequencies offer more specific information to analyse certain data set.

a student has an average of 76 on the first 5 quizzes, what average is needed on the next 5 quizzes to pull his quiz average up to an 80?

Answers

The student has an average of 76 on his first 5 quizzes. Remember that average is also known as mean. Mean is calculated by adding the values in a data set and dividing it by the amount of numbers you added.

In this case,the mean is 76. That means five numbers were added and divided by 5 and the quotient was 76.

$(x+x+x+x+x)/(5)=76$

You can find the dividend by cross multiplying.

$(x+x+x+x+x)/(5)=76 \rightarrow x+x+x+x+x=76 *5 \rightarrow 380$

The total points he got on his first 5 quizzes was 380.

If he wants to boost his average grade up to an 8 after taking another 5 quizzes, you need to multiply his average goal by the amount of quizzes, which is 10(5+5=10).

$80 * 10=800$

His total points after taking all his quizzes(that is, if he reached his goal) should be 800. Because he already took 5 quizzes and got a total score of 380, you're going to subtract 380 from 800 and divide it by the remaining quizzes left, which is 5.

First subtract 380 from 800:

$800-380=420$

That means his next 5 quizzes need to sum up to a total of 420 points. Since you're trying to find the average of his next 5 quizzes in order to average up to an 80, you need to divide 420 by 5(number of remaining quizzes).

Divide:

$420 / 5=84$

Your answer is 84(84%).

the formula for the area of a rectangle is a=lw , where a is the area, l is the length, and w is the width . a rectangular garden has a length of 10 ft. its width is 6 ft less than its length. what is the area of the garden? 14 ft² 16 ft² 40 ft² 60 ft²