Hospital floors are usually bare tiles instead of carpet. Carpets will decrease noise but might increase germ growth. To study this, researchers installed carpet in 8 of 16 hospital rooms. They randomly selected the rooms to carpet. The other rooms had bare tiles.
After two weeks of normal use, they collected air samples from the rooms and counted the bacteria in each sample. To identify the explanatory and response variables, match each of the following with one of the terms on the right. Note - any given term may be used more than once or not at all.
a. A control group
b. Direct control of confounding variables
c. Random assignment

answer: sensy

step-by-step explanation:

hi there!

the answer will be d: 2

d is the answer

step-by-step explanation:

d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

so the area of the floor is 108 square feet, converting that into square yards we get,

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

so, it will cost $300.