Which of the following is the best approximation of 3 times the positive square root of 19?

A. 57

B. 13.1

C. 21.7

D. 6.9

Answer Explanation:

We use the calculator to find the positive square root of 19, which is then multiplied by 3.

Using the calculator,

Multiplying the square root above with 3 becomes

The approximate value of 3 times the square root of 19 is 13.1.

Therefore, the Correct Answer is B.

Q #1: A circle has an area of 169 π in2. Which of the following is the circumference of the circle in terms of pi ( )?

A. 13 π in

B. 26 π in

C. 7.5 π in

D. 20 π in

Answer Explanation

We need to find the radius of the circle in order to find circumference of the circle. If we let r to be radius of the circle, then

Substituting 169π in place of area

Dividing both sides by pi and taking square root on both sides yields

The radius of the circle from the given area is 13 in. and the circumference of the circle is given by the relation:
Q #2: Which of the following values is the greatest?

A. 3/7

B. 6.98

C. 10/7

D. 9.2

Answer Explanation

To find the greatest number from the given options, convert the decimal numbers into fractions.

6.98 becomes 698/100

9.2 becomes 92/10

The least common denominator for the denominators of 7, 100 and 10 is 700. Now we can multiply each fraction with 700 as follows:

3/7*700=300

698/100*700=4886

10/7*700=1000

92/10*700=6440

In order from the smallest to largest, we organize the number set as follows:

3/7, 10/7, 6.98, 9.2.

Thus, 9.2 is the greatest of all.
Q #3: A person weighed themselves at 153 lb. Five months later they weighed themselves at 120 lb. Which of the following is the percent of weight the person lost over 5 months? (Round to the nearest percent.)

A. 38%

B. 22%

C. 19%

D. 29%

Answer Explanation

The percentage change in weight is found in three steps below:

Absolute change in weight=final weight-initial weight

Absolute change in weight= (left|120-153 ight|=left|-33 ight|=33)

Relative change in weight= (frac{absolute change}{initial weight}=frac{33}{153}=0.216)

Percent change=relative change * 100%

Percent change=0.216*100%=21.6%

The percent change in weight lost is 21.6 %, which is about 22%.