The number of chocolate chips in a popular brand of cookie is normally distributed with a mean of 21 chocolate chips per cookie and a standard deviation of 1.5 chips. When the cookies come out of the oven, only the middle 90% in terms of the number of chocolate chips are acceptable (the rest are considered defective). What are the cutoff numbers for the number of chocolate chips in acceptable cookies? (Give your answers to three decimal places) and Add Work

The strength of the welds in a new manufacturing process is measured by the amount of weight needed to break the weld. The strength of the welds is normally distributed with mean 583 pounds. 30% of the welds had strength less than 500 pounds. What is the standard deviation of the strength of the welds?

The time is takes a studen to walk from the dorn to the chemistry lab follows roughly a Normal distrubtion with a mean of 20 minutes and a stardard deviation of 3 minutes. What porportion of students is faster than 15 minutes when walking from the dorm to the chemistry lab?

The weights for newborn babies is approx normally distributed with a mean of 6.1 pounds and a standard deviation of 1.8 pounds. use the cumulative Z-score table to answer the following questions. Write your answers rounded to the nearest whole number.  consider a group of 1700 newborn babies: How many would you expect to weigh between 7.36 and 8.62 pounds?  How many would you expect to weigh less than 3.76 pounds? How many would you expect to weight more than 5.65 pounds?  How many would you expect to weight between 6.1 and 7 pounds?

A normally distributed data set has a mean of O and a standard deviation of 2. What is the percent of values between -6.0 and 6.0? (make sure to include % sign in answer.)

The average repair cost of a microwave oven is $55, with a standard deviation of $8. The costs are normally distributed. What is the range for the middle 50% of repair costs for microwave ovens? Label.