standard_description: Use variables to represent two quantities in a real-world problem that change in relationship to one another; write an equation to express one quantity, thought of as the dependent variable, in terms of the other quantity, thought of as the independent variable. Analyze the relationship between the dependent and independent variables using graphs and tables, and relate these to the equation. For example, in a problem involving motion at constant speed, list and graph ordered pairs of distances and times, and write the equation d = 65t to represent the relationship between distance and time.
problem_activity: Task
The ratio of the number of boys to the number of girls at school is 4:5.  There are 270 students at this school. For each of the following statements, explain whether the statement is true or false and why:
The number of boys at school is 4/5 the number of girls.
4/5 of the students in the school are boys.
There are exactly 30 more girls than boys.
There are exactly 30 boys at the school.
5/9 of the students in the school are girls.


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