An engineer designs an improved light bulb. The previous design had an average lifetime of 1200 hours. The new bulb has a lifetime of 1201 hours, using a sample of 2000 bulbs. Although the difference is quite small, the effect is statistically significant. The explanation is: a. that new designs typically have more variability than standard designs b. that the sample size is very large. c. that the mean of 1200 is large. d. all of the above

The number of nails of a given length is normally distributed with a mean length of 5.00 in, and a standard deviation of 0.03 in. find the number of nails in a bag of 120 that are less than 4.94 in. long.

Kapil needed to buy a long wooden beam. he went to two sawmills that each charge an initial fee plus an additional fee for each meter of wood. the following equation gives the price (in dollars) of a wooden beam from the first sawmill as a function of its length (in meters). p = 5+20xp=5+20x

Two students were asked if they liked to read. is this a good example of a statistical question? why or why not? a yes, this is a good statistical question because a variety of answers are given. b yes, this is a good statistical question because there are not a variety of answers that could be given. c no, this is not a good statistical question because there are not a variety of answers that could be given. no, this is not a good statistical question because there are a variety of answers that could be given