A 7 yr old medical research study reported that woman whose mothers took the drug DES during pregnancy were twice as likely to develop tissue abnormalities that might lead to cancer as were woman whose mothers did not take the drug.

a. This study involved comparison of two populations. What were the populations?
b. Do you suppose the data were obtained in a survey or experiment?
c. For the population of woman whose mother took the drug DES during pregnancy, a sample of 3980 woman showed that 63 developed tissue abnormatly that could lead to cancer. Provide a descriptive statistic that could beused to estimate the number of women out of 1000 in this population who have tissue abnormalities.
d. For the population of women wose mother did not take the drug during pregnancy, what is the estiimate of the number of woman out of 1000 who would be expected to have tissue abnornalities?
e. Medical sudies often use a relatively large sample (in this case 3980). Why?

Step-by-step explanation:

a)  This study involved comparison of two populations.

The populations are

i) woman whose mothers took the drug DES during pregnancy

ii) woman whose mothers did not take the drug DES during pregnancy

b) It was obtained in survey because past records were obtained and reports made

c) For I sample n = 3980 and x = 63

Hence for 1000 we can say it would be

approximately 16 persons

d) Information not given about this population

e) Medical studies always use a large sample because when sample size increases, std error decreases resulting a less margin of error.  Since health is concerned error should be kept at the bare minimum

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet

step-by-step explanation:

yes it represnts a functio, their are not 2 of the same numbers on the both sides