A student performs the following estimations.

35+192  230

258+350  610

947+1032  1980

Based on these estimations, which of the following is the student’s estimate of 694+7618?

: In order to solve for the value of x, we use the order of operations as follows:

The first step is to divide both sides by 3

Add 2 to both sides to eliminate it from the left-hand side of the equation

x-2+2=4+2

x = 6

Thus, the value of x is 6.

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.

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.

to find the average time the athlete runs in 1 mile, find total time divided by total distance covered in the two runs.

Total distance=5+3=8 miles

Total time=25+15=40 minutes

We now know that the athlete runs 8 miles in 40 minutes, so the time the athlete will run in 1 mile will be:  

In 5 minutes, the athlete runs 1 mile.

We usea calculator to find the product of

1.6*0.93=1.488

: 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.

: 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.

From the given estimations, we can find the exact sum after adding the given numbers and see the trend the student utilizes to find their estimates. The actual sum is as follows

26+180=206

115+391=506

497+2024=2521

From the above evaluation, the students round the exact sum to the nearest tens. So, in the problem we need to approximate 545+7501.

545+7501=8046

The exact sum is 8046 and the approximate value after rounding to the nearest tens is 8050.

In this problem, we need to find the amount of gratuity the couple will leave. The gratuity is 16% of the total bill. Before solving the problem, the following are terms and their meaning in percent problems:

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

If we let x be the amount of gratuity, then translating the given problem into a mathematical equation becomes:

So, the value of x=9.376 and to the nearest cent, x=9.38

There, a couple will leave a gratuity of $9.38.

To form an equation from the word problem, first break the given statement into smaller statements.

First, we are given the width of the rectangle as x. We are told, the length is two times width. Mathematically, this means

Length=2*width=2*x=2x

Now, the length is 6 less than 2 times width of the rectangle. Thus, the length of rectangle in terms of width becomes:

Length =2x-6

Thus, the length of the rectangle is 2x-6.