Bonnie has to maintain an average of 90 in all of her classes to have an A average. In Math, she has scored 93, 70, 99 and 95 on the first four tests. What must she score on the last test to have an average of 90?

Question

Bonnie has to maintain an average of 90 in all of her classes to have an A average.  In Math, she has scored 93, 70, 99 and 95 on the first four tests.  What must she score on the last test to have an average of 90?

Joe348 · Answer

you have to put the numbers in order 
so that would be 70, 93, 95, 99

Uknownunicorn · Answer

A	
85

B	
100

C	
93

D	
96

Uknownunicorn · Answer

A dance squad needs at least $800 to buy new dance outfits.

They have saved $350 already.
They are selling tickets to a dance performance for $8 each.
They need to sell x tickets to have enough money to buy the new dance outfits. Which inequality represents this situation?

A	
8x+350≥800

B	
8x+350≤800

C	
8(x+350)≥800

D	
8(x+350)≤800

Vocaloid · Answer

First problem:

the average of a set of values is:

(the sum of all the values) / (how many values there are)

so for your problem, the sum is the sum of all five test scores. she has already gotten 93, 70, 99 and 95 on the first four tests. we want to know what the fifth score must be. let's call that score "x"

so the sum is 93 + 70 + 99 + 95 + x

there are five total tests

she wants a 90 average

so, setting up the formula:

(93 + 70 + 99 + 95 + x) / 5 = 90, solve for x

Vocaloid · Answer

Second problem:

A dance squad needs at least $800 to buy new dance outfits.

They have saved $350 already.
They are selling tickets to a dance performance for $8 each.
They need to sell x tickets to have enough money to buy the new dance outfits. Which inequality represents this situation?

the tickets are $8 each. they are selling (x) tickets. therefore, the ticket revenue is 8*x or 8x

they already have 350 saved. so add 350 onto 8x.

now, because they want **at least** 800, set the sum greater than, or equal to, 800

what do you get?