Erin wants to know if warming up will help runners sprint faster. Twenty-six track and field athletes volunteered to participate in her study. She randomly assigns 13 athletes to warm-up for 10 minutes. All 26 participants sprint the same distance. She calculates the mean for each group and determines that the mean for the warm-up group was 10.9 seconds, and the mean for the other group was 12.9 seconds. To test the difference of means she re-randomized the data 54 times, and the differences are plotted in the dot plot below. What can Erin conclude from her study?

A dot plot is shown labeled from negative 2.5 to positive 2. Above the negative 2.5 are 3 dots. Above the negative 2 are 6 dots. Above the negative 1.5 are 9 dots. Above the negative 1 are 12 dots. Above the negative 0.5 are 6 dots. Above the 0.0 are 4 dots. Above the 0.5 are 3 dots. Above the 1.0 are 7 dots. Above the 1.5 are 3 dots. Above the 2.0 is 1 dot.

Option D "The difference in the means is significant because a difference of 2 is not very likely."

Step-by-step explanation:

I took the test and it was right.

i’m here for 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 ☺