In a study of breast cancer, a mother was considered exposed if she first gave birth at 30 years of age or older. among 1,628 mothers who were exposed, 31 subsequently developed breast cancer. among the 4,450 mothers who first gave birth before the age of 30, 65 subsequently developed breast cancer. what is the result for the appropriate measure to describe the strength of the association between age at first birth and breast cancer?

The theory says that one exposed mother is the one that gave birth after the 30s.

from 1628 exposed ones, 31 developed breast cancer, this means that a:

31/1628*100% = 1.9%

1.9% of the exposed sample developed cancer.

For the other part, of 4450 ones that weren't exposed, 65 developed cancer, the percent is:

65/4450*100% = 1.46%

So we can see that the ratio is smaller with the non-exposed ones.

The strength of the association can be calculated as:

(31/1628)/(65/4450) = 1.3

Meaning that an exposed person is 1.3 times more likely to develop cancer.

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.

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 ☺