Before hypothesis testing and at the beginning of a study, a researcher is advised to conduct because it . a. an effect size estimate; tells the researcher the number of participants needed for trustworthy results
b. alpha testing; determines how meaningful the study results will be
c. a statistical significance; determines how meaningful the study results will be
d. a power analysis; tells the researcher the number of participants needed for trustworthy results

d. a power analysis; tells the researcher the number of participants needed for trustworthy results.

Step-by-step explanation:

A control experiment can be defined as an experiment in which a condition assumed to be a probable cause of the effect is being compared to the same situation by the scientist without involving or using the suspected condition.

A hypothesis is considered to be tentative or an educated guess and can be defined as a testable explanation for an observation or a scientific problem. An example of a hypothesis is saying, Corona virus is caused by the introduction of the "5G" technology.

This ultimately implies that, for any hypothesis to be acceptable in science, it must be supported by observations and the results of control experiments; this give rise to factual informations, theories and by extension solutions to problems.

Before hypothesis testing and at the beginning of a study, a researcher is advised to conduct a power analysis because it tells the researcher the number of participants needed for trustworthy results.

A power analysis should always be conducted before the collection of data because it will help you as a researcher to determine the smallest sample size that's accurate enough to detect the effect of a specific test at the desired statistical significance level.

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.

(1,4) is on graph of f(x)

f(1) = 4

so 1/4 f(x)

1/4 f(1)

1/4. ×4

1

so point for function 1/4. f(x) is (1,1)