Due: 7 days from today Name: Person Number Recitation Exercise-Chapter 6 Answer

Question

Due: 7 days from today Name: Person Number Recitation Exercise-Chapter 6 Answer the following questions.You are allowed to work in groups, but everyone must show ALL of their work. Feel free to attach an additional sheet of paper. Note that your calculator might have function buttons that quickly compute critical values (eg, X,s2 etc.) and you should take advantage of them if you can. Harry, Ron, and Hermione are comparing their scores on a recent potions exam. They know the distribution of scores was normal with an average (mean) 79.5 and a standard deviation of 6.5 1) a.) What were their respective z-scores? Harry = 75; z- Ron-82.5; Hermione- 93 Z b.) Now plot their respective z-scores on the normal distribution below. (In terms of z- scores, not raw scores)

Explanation / Answer

Ans:

a)Given that mean=79.5,standard deviation=6.5

z=(x-mean)/std dev.

For Hary x=75

z=(75-79.5)/6.5=-0.69

For Ron x=82.5

z=(82.5-79.5)/6.5=0.46

For Hermione x=93

z=(93-79.5)6.5=2.08

2)a)P(x>93)=P(z>2.08)=1-P(z<=2.08)

=1-0.9812=0.0188

b)P(x<75)=P(z<-0.69)=0.2451

c)P(75 <=X<=82.5)=P(-0.69<=z<=0.46)=P(z<=0.46)-P(z<=-0.69)=0.6772-0.2451=0.4321

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

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