7학년 3분기 시험

Do the ratios form a proportion? Write yes or no.

1. 1
   $\frac{16}{4}\stackrel{?}{=}\frac{12}{3}$ 
2. 2
   $\frac{4}{10}\stackrel{?}{=}\frac{5}{2}$ 
3. 3
   $\frac{8}{28}\stackrel{?}{=}\frac{5}{21}$ 
4. 4
   $\frac{35}{25}\stackrel{?}{=}\frac{43}{30}$ 

Solve each proportion.

1. 5
   $\frac{1}{4}=\frac{5}{y}$
2. 6
   $\frac{35}{k}=\frac{40}{16}$

Write a proportion and solve it.

1. 7
   In a survey, $4$ out of $12$ students walk to school. Predict how many of $120$ students walk to school.

Find the constant of proportionality, k, for each table.

1. 8
   $\begin{array}{ccccc}x& 4& 7& 10& 13\\ y& 48& 84& 120& 156\end{array}$
2. 9
   $\begin{array}{ccccc}x& 2& 3& 4& 5\\ y& 7& 10.5& 14& 17.5\end{array}$

Write an equation in the form y = kx for each table.

1. 10
   $\begin{array}{ccccc}x& 1& 3& 5& 7\\ y& 0.4& 1.2& 2& 2.8\end{array}$
2. 11
   $\begin{array}{ccccc}x& 6& 9& 12& 15\\ y& 10& 15& 20& 25\end{array}$

Use the scale to answer each question.

1. 12
   A photo $5$ inches wide is enlarged to $12.5$ inches wide. What is the scale factor?

Answer each question.

1. 13
   What is $60\%$ of $190$?
2. 14
   What is $25\%$ of $152$?
3. 15
   What is $22\%$ of $400$?
4. 16
   What percent of $186$ is $93$?
5. 17
   What percent of $196$ is $235.2$?

Find each percent of change and write increase or decrease, or find the new amount.

1. 18
   $34$ to $51$: 
2. 19
   $95$ to $171$: 
3. 20
   $20$ to $21$: 
4. 21
   Increase $220$ by $5\%$: 

Answer each question.

1. 22
   A dinner bill is $\text{\$}66.00$. The family leaves a tip of $18\%$. How much is the tip?
2. 23
   A store buys a backpack for $\text{\$}24.00$ and marks the price up $25\%$. What is the selling price?

Use I = Prt to answer each question.

1. 24
   You put $\text{\$}750.00$ in a savings account that earns $2\%$ simple interest each year. How much money will be in the account after $6$ years?

Find the slope of each line.

1. 25
   Slope: 
2. 26
   Slope: 

Find the slope of the line through each pair of points.

1. 27
   $(0,-1)$ and $(-4,10)$ 
2. 28
   $(7,-8)$ and $(6,-4)$ 

Find the constant of proportionality, k.

1. 29
   k = 
2. 30
   k =