Which of these situations best describes a retrospective observational study? a.)
A student flipping a coin and analyzing its outcomes.

b.)
A doctor analyzing the medical history of a person.

c.)
A company using different promotions and analyzing its sales.

d.)
A clinical researcher giving a medicine to a person and analyzing its effects.

The correct answer is D. Elements are randomly selected from equal-sized blocks of the total population is NOT true regarding a randomized block design experiment

From the question we are told that one statement is NOT true regarding a randomized block design experiment.

Where

D) Elements are randomly selected from equal-sized blocks of the total population is Not True

In conclusion

The all other Options are true except option D which states that Elements are randomly selected from equal-sized blocks of the total population.

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answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11

answer: answer: d) v= 1/6 bh  

step-by-step explanation:

since according to the given question,   a pyramid is placed inside a prism.

step-by-step explanation: