The following scatter plot depicts the number of chicken pox cases after 1988. The variable x represents the number of years after 1988. The variable y represents the number of cases in thousands.
200
280
260
Reported Cases (thousands)
140
220
4
200
0 2 2 3 5 6
Number of years after 1988
Does there appear to be a linear relationship? Explain your answer.
a. Yes, there is a linear relationship. The data appears to have a negative correlation.
b. Yes, there is a linear relationship. The data appears to have a positive correlation.
C. No, there is not a linear relationship. The data seems random.
d. No, there is not a linear relationship. There is no line which goes through all the points.

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺

60: 45 =12: 9 =4: 3 so the answer is 4: 3