Marcos works 8 hours a day. he makes $19 an hour. on tuesday, he only worked of a day. how much did marcos earn on tuesday?
which answer gives the correct solution and explains how to check if the answer is reasonable?
a.
solution: $57.
explanation: since marcos only worked of the day,
he made about 3 × $20 or about $60.
b.
solution: $456.
explanation: since marcos only worked of the day,
he earned about 3 × $20 or about $60.
since there are 8 hours in the work day,
then marcos made about 8 × $60 or about $480.
c.
solution: $114.
explanation: if marcos worked all day,
then he would have made about 8 × $20 or about $160.
since marcos only worked of the day, or 0.75,
he would make about $120 (160 × 0.75).

Aresearch study is studying the effects of a new drug for osteoporosis alzheimer's disease (ad) for women above the age of 65 years. a group of individuals with osteoporosis is randomized into two groups. one group is treated conventionally, and the second group is treated with the new medication. assessments are made at 3, 6, 12, 36, and 48 months. the conventionally treated group is assessed for ad using a serum blood test, and the treatment group is assessed for ad using a pet radiotracer that binds to beta-amyloid plaques. in comparing these 2 trial arms, the authors of the study may encounter which type of bias? a. selection bias on the risk of developing b. measurement bias c. confounding bias d. recall bias e. lead-time bias