A pizza shop claims its average home delivery time is 23 minutes. A sample of 30

Question

A pizza shop claims its average home delivery time is 23 minutes. A sample of 30 deliveries had a sample average of 25.4 minutes. Assume the population standard deviation for the shop's deliveries is 6.5 minutes. Complete parts a and b below. a. Is there support for the shop's claim using the criteria that the sample average of 25.4 minutes falls within the symmetrical interval that includes 95% of the sample means if the true population mean is 23 minutes? Select the correct choice below and fill in the answer box within your choice. (Type an integer or decimal rounded to four decimal places as needed.) O A. The probability P (x2 254)-1 . This indicates that the sample average of 25.4 minutes falls outside the 95% symmetrical B. The probability P x2 25.4) This indicates that the sample average of 25.4 minutes falls within the 95% sy metrical interval, supporting the shop's claim.

Explanation / Answer

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

here P(Xbar>=25.4)=P(Z>(25.4-23)/(6.5/sqrt(30))=P(Z>2.02)=0.0217

option A is correct: the probability P(Xbar>25.4)=0.0217 ( please try 0.0216 if this comes wrong)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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