Simplify the expression below. Which of the following is correct?

3.45 * 0.53

: 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.

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

The babies' measured weights change over time and depend on the time interval after birth. Since weight is the outcome being measured, it is the dependent variable in the study.

We know that 1 L =1000 mL, which we use to convert between the two units. The conversion fractions of interconverting are:

And

Since we want to end up with millimeters, the second conversion is used in converting L to mL as:

Thus, 3.2 L is equivalent to 3200 mL.

We need to find how many mL are in 5.5 teaspoons. We are told that 1 teaspoon is about 4.93 mL, which we interpret as follows:

Or

Since we are looking for mL, we use the second option.

Thus, 5.5 teaspoons can hold approximately 27 mL.

correlations fall into positive, negative, and no correlation. A positive correlation shows that an increase in one variable increase results in an increase on the other variable increases as shown.

A negative correlation scatter plot shows that an increase in one variable results in a decrease on the other one.

The no-correlation scatter plot demonstrates that there is no response between variables. A change in one variable has no effect on the other variable.

Looking at the provided scatter plot, the heights of the students does not have any relationship on the students’ scores. Thus, the type of correlation is no correlation.

 we are to find the selling price of the sweater from the marked price and the discount. The marked price is given as

Discount=mark off rate*original price

Discount=15%*$78

Convert 15% into a fraction, which become 15/100=0.15. Then

Discount=0.15*$78=$11.70

The selling price of the sweater will be the original price less the discount or mark off value. Then,

Thus, the approximate selling price of the sweater is $66.

: 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.

Let's calculate the number of each color of gumball:

• Red: 20% of 120 → 0.2×120=24
• Orange: 30% of 120 → 0.3×120=36
• Yellow: 5% of 120 → 0.05×120=6
• Green: 10% of 120 → 0.1×120=12
• Blue: The remaining percentage: 100%−(20%+30%+5%+10%) = 100%−65% =35%
• So, 0.35×120=42 blue gumballs.

Now, we find how many more blue gumballs there are than yellow:

42−6=36

: We need to find the total rainfall for the months of May, June, and July using the given graph.

In the month of May, rainfall is between 3 and 4, which is halfway. Therefore, rainfall in May is 3.5 inches

On June, rainfall was 3 inch and on July the rainfall was 2.5 inches. Thus,

Total rainfall=3.5 inches+3 inches+ 2.5 inches=9.0 inches