The following graph shows the normal distribution of the results of an algebra test a class of 22 students took. the median of the results was 80 points out of 100, with a standard deviation of 6 points. which of the following numbers is closest to the number of students that got more than 86 but less than 92 points? 1 3 7 9

, and

for

step-by-step explanation:

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

note the following:

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