FILEA research analyst follows the biotechnology industry and examines the daily stock price of Amgen, Inc. over the past year. The table below shows a portion of the daily stock price of Amgen for the 252 trading days in 2010; the full data set can be found on the text website, labeled Amgen. The research analyst wants to test the random-walk hypothesis that suggests that stock prices move randomly overtim e w ith no discernible pattern.

Date Adjusted Stock Price 1/4/2010 $57.72 1/5/2010 57.22 12/31/2010 54.9

a. Use the method of runs above and below the median to test the null hypothesis of randomness against the alternative that there is a trend at the 5% significance level.

b. Can the research analyst conclude that the movement of Amgen's stock price is consistent w ith the random-walk hypothesis?