Xavier surveyed a random sample of the grade levels of the Spanish Club members in the county. The bar graph shows the results of his survey. If there are 300 students in the Spanish Club in the county, predict how many are 10th graders.

, 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

use distributive property on all like terms and change your signs if you have a double negative or if you have positive/negative

ok so what's the question?

step-by-step explanation: