A new pet food product for small dogs has been developed to help with tooth decay. Fifty-two dogs participate in the study. Each dog owner picks a card from a standard deck out of a hat. If the card is red, their dog will be in the treatment group. If the card is black, their dog will be in the placebo group. Which experimental design was used? a. Randomized Block Design
b. Completely Randomized Design
c. Case-Control Design
d. Matched-Pair Design

B. Completely Randomized Design

Step-by-step explanation:

A completely randomized design is an experimental design such that treatments are assigned at random completely in order for each experimental unit to have same chance of receiving treatment.

In this scenario, since all the dogs are randomly assigned treatment by picking a card without taking into consideration other factors, then we can infer that thus is a completely randomized design.

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a