lll adults over 50 glasses for driving. In a random sample of 6 adults over 50,

Question

lll adults over 50 glasses for driving. In a random sample of 6 adults over 50, find the probability that at most five of them wear glasses for driving to the nearest hundredth percent. 29. A student answ test by random represents the m normal distribu the student gets to two decimal (25-28) Assume that the salaries of elementary school teachers in the United States are normally distributed with a mean of $52,000 and a standard deviation of $6,000. ow many teachers have a salary less than $60,000? Round to the nearest percent. 25. H 30. Assume that sc distributed wit deviation of 7 find the proba greater than 2 26. How many teachers have a salary above $40,0002 Round to the nearest percent.

Explanation / Answer

25)

P(X < 60000) = P(Z < 60000 - 52000/6000)

= P(Z < 1.333)

= 0.9088

26)

P(X>40000) = P(Z > 40000-52000/6000)

= P(Z >-2)

= 0.9772

27)

P(45000 < X < 55000)

= P(X < 55000) - P(X < 45000)

= P(Z < 55000-52000/6000) - P(Z < 45000-52000/6000)

= P(Z < 0.5) - P(Z < -1.1667)

= 0.6915 - 0.1217

= 0.5698

28)

P(X > a) = 0.25

P(Z > a-52000/6000) = 0.25

a-52000/6000 = 1 - invnorm(0.25)

=>

a = (1-(-0.674)) * 6000 + 52000

= 62044

Related Questions

Navigate

• Browse (All)
• Browse L
• Subjects

---

---

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