× Chegg Study Guided Souto X ?? c Secure! https:// edugen.wileyplus.com/edugen/l

Question

× Chegg Study Guided Souto X ?? c Secure! https:// edugen.wileyplus.com/edugen/ltimain.uni Lock, Statistics: Unlocking the Power of Data, 2e PRINTER VERSION BACK NEXT ASSIGNMENT RESOURCES Sum18-Assignment 4 Finding probabilities for a sample mean result - engines The engines made by Ford for speedboats had an average power of 220 horsepower (HP) and standard deviation of 15 HP. A buyer is only interested in purchasing if the mean HP for the sample of engines is more than 215 HP. If they sample 10 engines, what is the probability that the sample mean is more than 215 HP? x Assume the original distribution is normally distributed. Round your answer to nearest thousandth. Chapter P. Section 5 Chapter P. Section 5. Chapter P. Section 5 exact number, no toierance Chapter 6, Section 1-D Question Attempts: 0 of 1 used SAVE FOR LATER SUBMIT ANSWER Excriso 010 phat- praportion f sample mean result Review Score Review Results by Study Objective

Explanation / Answer

here std error of mean =std deviation/sqrt(n)=15/sqrt(10)

as z score=(X-mean)/std error

hence P(sample mean is more than 215)=P(Xbar>215)=P(Z>(215-220)/(15/sqrt(10))=P(Z>-1.05) =0.853

(please try 0.854 if this comes wrong)

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

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