From the table, for every 6 containers of water, you need 8 containers of red dye. So, for every one container of red dye you need 0.75 containers of water (6/8). Then, multiply that by 100 (since you wanted to know water necessary for 100 containers of red dye). For 100 containers of red dye, you would need 75 containers of water.
D. The exclusion is important because we cannot divide by zero. Apart from that we are simply looking at a function.
Answer:

And we can assume a normal distribution and then we can solve the problem with the z score formula given by:

And replacing we got:


We can find the probability of interest using the normal standard table and with the following difference:

Step-by-step explanation:
Let X the random variable who represent the expense and we assume the following parameters:

And for this case we want to find the percent of his expense between 38.6 and 57.8 so we want this probability:

And we can assume a normal distribution and then we can solve the problem with the z score formula given by:

And replacing we got:


We can find the probability of interest using the normal standard table and with the following difference:

When rounding, look to the next place to the right of what you are rounding to... for example if you are rounding to the nearest hundredth, look to the thousandths place to see if the hundredths place rounds up or down. Since your number, 615.44 stops on the hundredths place, the thousandths place is automatically zero, so your number stays the same.
615.44