64x2.40 = 153.6
64x1.90 = 121.6
add 153.6 to 121.6
275.2
Answer:
The answer is 1
Step-by-step explanation:
The answer is Internal Validity.
Internal Validity is high in an experiment. when it demonstrates persuasively that changes in behavior are caused by the independent variable and not by unknown factors.
What is Internal Validity?
- Internal validity is defined as the degree to which the observed results represent the truth in the population under investigation and are not the consequence of methodological flaws.
- Internal validity is the degree of certainty that the causal link being examined is reliable and unaffected by other factors or variables.
- The extent to which study results may be extended (generalized) to other contexts, groups, or events is referred to as external validity.
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Answer: it is 12 the second one
