Bob has a bulb factory that produces two types of bulbs: white light (x) and color light (y). It is known that the standard deviation of service life for the population of white light bulbs is hours and hours for color bulbs, both are normally distributed. He tested the mean service life of those two types of bulbs by randomly drawing a sample of 20 bulbs from each type. The estimated mean service life are hours and hours. Assume that . What is the absolute value of the t-statistic if the null hypothesis is that both types of bulbs have the same service life?

Write an algebraic expression to match each statement a. four less than 8 times a number b. twice the difference of a number and six c. nine from a number squared

When a 757 passenger jet begins its descent to the ronald reagan national airport in washington, d.c., it is 3900 feet from the ground. its angle of descent is 6 degrees. how far must the plane fly to reach the run way? a. 37,106 ft b. 37,310.4 ft c. 23,456.6 ft d 2,492.7 ft

Identify the statement below as either descriptive or inferential statistics. upper a certain website sold an average of 117 books per day last week. is the statement an example of descriptive or inferential statistics? a. it is an example of descriptive statistics because it uses a sample to make a claim about a population. b. it is an example of inferential statistics because it uses a sample to make a claim about a population. c. it is an example of inferential statistics because it summarizes the information in a sample. d. it is an example of descriptive statistics because it summarizes the information in a sample.