Chevron Company reports the mean price per gallon of regular gasoline $3.10, wit

Question

Chevron Company reports the mean price per gallon of regular gasoline $3.10, with a population standard deviation of $0.20. Assume a random sample of 16 gasoline stations is selected and their mean cost for regular gasoline is computed. a. What is the likelihood the sample mean is greater than $3.08? b. What is the standard error of the mean? According to PG&E; Company, the amounts of utility bills for all households in a city have a skewed probability distribution with a mean of $140 and a standard deviation of $30. Find the probability that the mean amount of bills for a randomly selected sample of 75 households will be a. between $132 and $136 b. within $6 of the population mean c. more than the population mean by at least $4

Explanation / Answer

20.

a. P(132<X<136)
= P(132-140/(30/sqrt(75)<Z< 136-140/(30/sqrt(75))
= P(-2.31<Z<-2.15)
=.0158-.0104
=.0054

b.P(|X-Mu|<=6)
= P(Z<= 6/(30/sqrt(75))
=P(Z<1.732)
=.9583

c.P(|X-mu|>=4)
=P(Z>=4/(30/sqrt(75))
=P(Z>=1.15)
=1-.8749
=.125

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

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