large company buys thousands of light bulbs every year. The company is currently considering

three brands of light bulbs to choose from. Before the company decides which light bulbs to buy,

it wants to investigate if the mean lifetimes of the three types of light bulbs are the same. The

company's research department randomly selected a few bulbs of each type and tested them. The

following table lists the number of hours (in thousands) that each of the bulbs in each brand lasted

before being burned out.

Brand I Brand II Brand III

15 20 21

18 23 22

18 22

*indicatesa value obtained from the 4th and 5th digits of your ID.

(a) At 5% significance level, test the null hypothesis that the mean lifetime of bulbs for each

of three brands is the same.

(b) Also Construct ANOVA table mentioning all necessary columns for this above example.