Questions from Business Statistics

Q: The article “Kids Digital Day: Almost 8 Hours” (

The article “Kids Digital Day: Almost 8 Hours” (USA TODAY, January 20, 2010) summarized a national survey of 2002 Americans age 8 to 18. The sample was selected to be representative of Americans in th...

Q: A consumer group is interested in estimating the proportion of packages of

A consumer group is interested in estimating the proportion of packages of ground beef sold at a particular store that have an actual fat content exceeding the fat content stated on the label. How man...

Q: Let z denote a random variable that has a standard normal distribution

Let z denote a random variable that has a standard normal distribution. Determine each of the following probabilities: a. P(z < 2.36) b. P(z ≤ 2.36) c. P(z < 21.23) d. P(1.14 < z , 3.35) e. P(20.7...

Q: Consider the population of all one-gallon cans of dusty rose

Consider the population of all one-gallon cans of dusty rose paint manufactured by a particular paint company. Suppose that a normal distribution with mean u = 5 ml and standard deviation σ = 0.2 ml i...

Q: Suppose that the distribution of typing speed in words per minute (

Suppose that the distribution of typing speed in words per minute (wpm) for experienced typists using a new type of split keyboard can be approximated by a normal curve with mean 60 wpm and standard d...

Q: A machine that cuts corks for wine bottles operates in such a

A machine that cuts corks for wine bottles operates in such a way that the distribution of the diameter of the corks produced is well approximated by a normal distribution with mean 3 cm and standard...

Q: Refer to the previous exercise. Suppose that there are two machines

Refer to the previous exercise. Suppose that there are two machines available for cutting corks. The machine described in the preceding problem produces corks with diameters that are approximately nor...

Q: Determine each of the following areas under the standard normal (z

Determine each of the following areas under the standard normal (z) curve: a. To the left of -1.28 b. To the right of 1.28 c. Between -1 and 2 d. To the right of 0 e. To the right of -5 f. Betwee...

Q: Let z denote a random variable having a normal distribution with µ

Let z denote a random variable having a normal distribution with µ = 0 and σ = 1. Determine each of the following probabilities: a. P(z < 0.10) b. P(z < 20.10) c. P(0.40 < z < 0.85) d. P(20.85 < z...

Q: The article “new york city’s graffiti-removal response time rises

The article “new york city’s graffiti-removal response time rises” (The Wall Street Journal, September 16, 2016, www.wsj.com/articles/new-york-citys-graffiti-removal -response-time-rises-1473287392, r...