Question

What would the equation be if the concentration of medicine decreased by 30% each hour?
Responses

y is equal to 400 times 0 point 7 to the x th power

y is equal to 400 times 30 to the x th power

y is equal to 400 times 1 point 3 to the x th power

y is equal to 400 times 0.7 to the x th power