SOLUTION: following the guidelines of the Food and Drug Administration, Dale tries to eat at least 5 servings of fruit each day. For the first six days of one week, she had 5,5,3,5,4, and 5

Algebra ->  Linear-equations -> SOLUTION: following the guidelines of the Food and Drug Administration, Dale tries to eat at least 5 servings of fruit each day. For the first six days of one week, she had 5,5,3,5,4, and 5       Log On


   

Question 178269: following the guidelines of the Food and Drug Administration, Dale tries to eat at least 5 servings of fruit each day. For the first six days of one week, she had 5,5,3,5,4, and 5 servings. How many servings of fruit should Dale eat on Saturday to average at least 5 servings per day for the week?
Answer by EMStelley(208) About Me  (Show Source):
You can put this solution on YOUR website!
Well, first a good question to ask might be what is the average so far? That would be
%285%2B5%2B3%2B5%2B4%2B5%29%2F6=27%2F6=4.5
So, so far he has averaged 4.5 servings of fruit a day. So we need to up it to 5. Let's call the number of servings of fruit he needs to eat on the last day x. Then we want
%285%2B5%2B3%2B5%2B4%2B5%2Bx%29%2F7=5
Note that since we want the average to be at least 5, solving the equation equal to 5 will tell us the minimum number of servings he needs to eat. So the first step would be to multiply both sides by 7.
5%2B5%2B3%2B5%2B4%2B5%2Bx=35
Now, we combine like terms on the left hand side:
27%2Bx=35
Last, subtract 27 from both sides
x=8
So he needs to eat at least 8 servings of fruit on the last day to average 5 for the week.