Ella’s test grades in her history class are 89, 94, 82, 84, and 98. what score must ella make on her next test to have a mean test score of 90?

Mean is same as average

to find average
add up terms
divided that sum by the number of terms you have
example

mean of x,y,z
x+y+z
3 terms
(x+y+z)/3=mean

so
represent next test score as x
89+94+82+84+98+x
count how many terms ther are (6 terms)

mean is 90
(89+94+82+84+98+x)/6=90
add the like terms
(447+x)/6=90
multiply both sides by 6 to clear fraction
447+x=540
subtract 447 from both sides
x=93

she needs a score of 93 on next test

10,000 hope i ! : )

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

1 the 1st term, 3 the 2nd term, 6 the 3rd term,etc.

note the following:

from the 1st term (1) to the 2nd term (3), we go up by 2,from the 2nd term (3) to the 3rd term (6), we go up by 3from the 3rd term (6) to the 4th term (10), we go up by 4, andfrom the 4th term (10) to the 5th term (15), we go up by 5.

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for