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Dmitriy789 [7]
3 years ago
5

Theo was doing research to support the claim that exercise increases heart and lung health. He had 50 people do a rigorous exerc

ise 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?

It is valid because he used multiple trials.
It is invalid because he did not have a control group.
It is invalid because his sample size was small.
It is valid because he controlled the exercise program.
Biology
2 answers:
Aliun [14]3 years ago
7 0

Answer:

i have A for my answer

Explanation:

It is valid because he used multiple trials.

pls mark me as brainliest if this helped :D

pishuonlain [190]3 years ago
4 0

Answer:

b

Explanation:

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