What are the mean and the standard deviation for this population? b. : 75,0 5 3)

Question

What are the mean and the standard deviation for this population? b. : 75,0 5 3) Professor Chao's engineering final exam has a mean of-79 and 7. After standardizing the exam scores, the mean is 80 and 5. How did Professor Chao arrive at these new standardized scores for the exam? a. Deciding what values will be simple to calculate d. Selecting the nearest values that are multiples 4) As part of a clinical research project, a sample population has been using an experimental drug intended to improve memory. Study participants completed a comprehensive memory test following six weeks of treatment. The results were standardized and compared to mean results for the full population. Which of the following participants indicates promising results for this drug treatment? a. Ahmad, a 61-year-old man with a memory test z-score of +.50 b. Ellie, a 52-year-old woman with a memory test z-score of +2.75 c. Javier, a 48-year-old man with a memory test z-score of 25

Explanation / Answer

Please post 1 question per post, as per forum rules.

Let a and b be mean and standard deviation.

X = 60 has a Z = -3

So, (X-a)/b = -3

X +3b = a, where X=60

60+3b = a...1

X = 85 has a Z = 2

So, (X-a)/b = 2

85-2b = a...2

So, equating 1 and 2..we have:

60+3b = 85-2b

5b = 25

b =5

So, 85-2*5 = 75 = a

Hence, b option is correct

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.