3) You work at a movie theater part time as you go to school. As part of the ENG

Question

3) You work at a movie theater part time as you go to school. As part of the ENGR 345 project you measure the weight of popcorn into a theater cup. The machine dispenses popcorn into cartons previously labeled "12 ounces." The machine has a setting to adjust the mean amount dispensed, but you have no idea about the standard deviation is. Suppose that you set the dispenser at 12.5 ounces, and you find that approximately 9% (exactly 0.0901) of the cartons are underweight (bclow 12 ounces). a) What is the standard deviation? -05/-1 .34 = 0.37 Apparently the standard deviation of the amount dispensed is about 0.37 ounce. b) Using the standard deviation from above, what weight are the 95% of the popcorn boxes filled to?

Explanation / Answer

a) for 9 percentile ; z=-1.3408

therefore std deviation =(X-mean)/z score =(12-12.5)/(-1.3408)=0.3729

b)

for middle 95% values ; z score =-/+ 1.96

therefore middle 95 % values =mean -/+ z*std deviaiton =12.5 -/+ 1.96*0.3729 =11.77 to 13.23 ounce

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

---

---

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