At an initial examination in oxford, massachusetts, migraine headache was found in 5 of 1,000 men aged 30 to 35 years and 10 in 1,000 women aged 30 to 35 years. the inference that women have a two times greater risk of developing migraine headache than do men in this age is:
a) incorrect, because a ratio has been used to compare male and female rates
b) incorrect, because of failure to recognize the effect of age in the two groups
c) incorrect, because no data for a comparison (control) group are given
d) incorrect, because of failure to distinguish between incidence and prevalence

D) Incorrect, because of failure to distinguish between incidence and prevalence

Explanation:

YES!, the inference was incorrect because we no information was given about the emergence of the migraine or effect that resulted to it. Also, the inference made from such observation  is void and not applicable.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

c

explanation: