A study studied the birth weights of 2,454 babies born in the United States. The

Question

A study studied the birth weights of 2,454 babies born in the United States. The mean weight was 3234 grams with a standard deviation of 871 grams. Assume that birth weight data are approximately bell-shaped, estimate the number of newborns who weighed between 1492 grams and 49/6 grams. Write only a number as your answer. Round your answer to the nearest whole number. For a certain type of truck, the mean number of miles per gallon is 21.6 and the standard deviation 4.9. Assume gas mileage for this type of truck to be approximately bell shaped. Compute the z-score for a truck whose gas mileage is 17. Write only a number as your answer. Round your answer to two decimal places (for example: 3.15).

Explanation / Answer

1. Let us first convert x to z=x-mu/sd

z1=(1492-3234)/(871)=-2

z2=(4976-3234)/871=2

So we need to find P(-2<z<2)=0.9545

2. z score is x-mu/sd=17-21.8/4.9=-0.98

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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