Which of the following principles of experimental design reduces errors due
to chance by repeating an experiment on different subjects under different
conditions?
A. Placebo effect
B. Replication
C. Randomization
D. Control
E. Blindness

List the elements of the set in roster notation. (enter empty or ∅ for the empty set.) {x | x is a letter in the word hippopotamus}

Answer these questions showing your work plz

Mexico city, mexico, is the world's second largest metropolis and is also one of its fastest-growing cities with a projected growth rate of 3.2% per year. its population in 1991 was 20,899,000 people. use the formula p = 20.899e0.032t to predict its population p in millions with t equal to the number of years after 1991. what is the predicted population to the nearest thousand of mexico city for the year 2010?