Final answer:
To find the time to type 400 words at 30 words per minute, set up the proportion 30/1 = 400/x and solve for x, giving 13.33 minutes. To find how many words you can type in 10 minutes, set up the proportion 30/1 = y/10 and solve for y, resulting in 300 words.
Step-by-step explanation:
Setting up and Solving Proportions
To determine how long it would take to type 400 words at a rate of 30 words per minute, we need to set up a proportion. A proportion is an equation that states two ratios are equivalent.
Part a: Setting up the proportion
If you type 30 words per minute, then a proportional rate for x minutes to type 400 words can be set up as:
30 words/1 minute = 400 words/x minutes.
Part b: Solving the proportion
By cross-multiplication, we solve for x: (30 words) * (x minutes) = (400 words) * (1 minute). This simplifies to 30x = 400, thus x = 400/30, which equals 13.33 minutes.
Part c: Setting up another proportion
Now, to find out how many words you can type in 10 minutes, we set up another proportion based on the original rate: 30 words/1 minute = y words/10 minutes.
Part d: Solving the second proportion
Again using cross-multiplication: (30 words) * (10 minutes) = (1 minute) * (y words), which gives 300 = y.
So, you can type 300 words in 10 minutes.