For fun question

find the formula for how many items are in a 2 deimentional pyramid (each row is 1 more than previous row like in attachment) when you have n number of rows

n=number of rows
n, x means when you have n rows, you have x items in pyramid

n=1, 1
n=2, 3
n=3, 6
n=4, 10
n=5, 15

find the number of items when you have n number of rows
f(n)=something

show all work and logic
no googling to find answer or just putting the answer

Paint color preference children adults total 0.6 0.77 liked new paint color disliked new paint color 0.4 0.15 0.23 total 1.0 1.0 1.0 which value for x completes the conditional relative frequency table by column?

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )