Notice that 50 minutes is twice the half-life.
After 25 minutes, half of the starting amount remains, so that 88g decays to 44g.
After another 25 minutes (a total of 50 minutes), the 44g will decay to 22g.
If you add a zero to the ones place to level the numbers out it should look like this

and count the numbers from 0.325 to 0.350
I believe it is A and Yes
The bigger the price is on an item, the more tax you would have to pay, so both numbers increase. As for whether or not there is a line through the dots, you use a line when you could go inbetween the points. For example, with this question you can have 0.24, 0.86, or any other number as the price and it would make sense. If the question was sales tax on a certain number of shirts, well, you can't buy half a shirt so you don't need anywhere inbetween the dots.
Proportional in these kinds of problems means whether or not the line curves. If it doesn't and is a straight line, then it is proportional.
Answer:
Angela, a proportion is two equal ratios, kinda like 3/4 = 6/8.
If we call the number of cars c, then our proportion is 3/10 = c/100.
Cross multiplying, we get 10c = 300.
Dividing both sides by 10, c = 30.