Answered

1. Sarah has an average of 92.5 for her 3 science tests. What does she need to make on the 4th test to get a 94% average. 

2.The pep club is selling flower arrangements with a choice of 4 different types of flowers, 3 kinds of greenery, and with or without baby's breath. How many different flower arrangement's do they offer.

Please give me the explanations, not just the answers. Also please hurry, I need the answers quick.

Thanks!



Answer :

secretlyblu
1) set up a problem
you know you want to get an avg of 94 but how do you do avg in the first place. you add up the numbers then divde by the total number of numbers used lol

so [tex] \frac{92.5+x}{2}=94 [/tex]
92.5 is the avg number for the last 3 tests
"x" is the 4th test score which we want to find out
"2" is the total number of numbers being added together

so now lets get x to one side

92.5+ x=94*2 (multiply 2 to both sides)
92.5+x=188
x=188-92.5  (subtract 92.5 from both sides)
x= 95.5  this is the score she need to make to avg 94%

2) you can draw a tree diagram. for example Flower1 branches off into 3 diff greens and then each of those greens branch off into 2 for with or with babies breath.

or you can simple multiply 4*3*2. you can do this because all choices are included with no restriction

your total number of options is 24