Please hurry Theo was doing research to support the claim that
exercise increases heart and lung health. He had 50
people do a rigorous exercise program. Each week, for
six months, he tested their heart and respiratory rate. He
determined that exercise does increase heart and lung
health.

Which best describes his claim?

A-It is valid because he used multiple trials.

B-It is invalid because he did not have a control group

C-It is invalid because his sample size was small.

D- It is valid because he controlled the exercise
program.

the answer is simply just 6n add the two together as they have an n

d. it is a convex pentagon because it has five sides and none of the sides would extend into the inside of the polygon.

step-by-step explanation:

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."