Which of the following relationships represents a no correlation between two variables?

 

When solving percent problems, the following words and their meaning becomes handy.

• Is means equals
• Of means multiply
• What means unknown (variable)

If we let x represent the amount of tip the couple want to leave behind, then

So, the couple will leave a tip of $2.84, which is about $3.00

Explanation: We know that 1 L=1000 mL and to change between L and mL we use the following two options

To solve the equation this equation, we use a calculator and find the product as:

3.45 * 0.53= 1.8285

Correlation of two variables falls into:

Positive correlation: an increase in one variable causes another variable to increase

Negative correlation: an increase in one variable causes another one to decrease

No correlation: a change in one variable does not cause any response in another variable.

From the given choices

Option a is no correlation

Option b is a negative correlation

Option c is a negative correlation

Option d is a positive correlation

Thus, the correct statement is a.

Histograms are used to present frequency of data of one variable over the other. On the other hand, a bar graph is used to compare the two variables with the rectangles not touching one another as in histograms. Scatter plots are used to show the correlations between two variables. In this case, the teacher will be able to use scatter plot to establish the correlation between test scores and the subjects.

: the question requires we find the cost of four syringes.

If we let x be the cost of four syringes, then we set up a proportion equation with cost as numerator and number of syringes as denominator. The proportion equation becomes

Cross-multiply to solve for x

Rearranging the above

Divide both sides of the equation by 55

Thus, the cost of 4 syringes is $48.

we are asked to find the largest value from the options given. To solve this problem, we need to convert all the given values into fraction. Then find the least common denominator for all fractions, which we will use to multiply each fraction and make a comparison.

43÷55=43/55

5/7

0.729=729/1000

73%=73/100

Now, we need to find the least common denominator of 55, 7, 1000, and 100, which is 77000. We multiply each fraction by 77000 as follows:

43/55*77000=60200

5/7*77000=55000

729/1000*77000=56133

73/100*77000=56210

From the calculated values, it can be noted that 43/55 is the greatest value among the given options.

: a ratio can be thought of a fraction of the form a/b, where b is not equal to zero. In ratio form, to means per.

Now, the class has 26 girls and 22 boys. Thus, the ratio of girls to boys becomes:

The fraction above reduces into

In ratio form, girls: boys=13:11

Thus, the ratio of girls to boys in a class of 48 students is 13 to 11.

Before we compare the values of the options, we convert the decimals to fractions.

5.4 becomes 54/10

6.25 becomes 625/100

Thus, the set of fractions is 11/2, 54/10, 13/3, 625/100. The least common denominator for 2, 10, 3, and 100 is 300, which we use to compare each options given.

11/2*300=1650

54/10*300=1620

13/3*300=1300

625/100*300=1875

From the above, 1875 is the greatest value which corresponds to 6.25. Therefore, 6.25 is the greatest value of all the choices given.

from the given data, one gallon of cleaning solution requires 6 oz of ammonia. The mathematical expression of this statement can be expressed in two ways:

Or

The question requires we find the amount of ammonia needed to make 230 gallons of the solution. So, we use the second option and proceed as follows:

From the above equation, gallon of solution will cancel, and oz of ammonia is left.

Therefore, the solution will require 1380 oz of ammonia.