Please provide a step-by-step explanation and please refrain from using any sort of software in your explanation, as I won't be able to use any software during my exam. If you can please use statistical calculators that'd be appreciated as I have a Casio FX-9750 GII

Question 5 The table below is a random sample of 20 companies whose stock is traded on the New York Stock Exchange. For each company, the number of shares traded on May 25, 1999, and May 26, 1999, is given. At the 0.05 level of significance, is there evidence of a difference in the average number of shares traded on these two days? Shares Traded Company 25-May 26-May Airgas 120500 109500 AonCp 1343500 629000 BWAY 4100 1700 Calpine 95000 298600 Chubb 1207600 959500 EDO 17100 9900 Ferro 59100 78000 GTE 9161001423800 HshldInt 22531001580400 Katy Ind 3500 1400 LTV Cp 686000 555200 MutiRisk 78600 26500 NortelNtwks 12705001856000 RangerOil 40700 98200 Repsol 119800 82500 SalomonWld 13500 60700 Tefron 22300 30400 TritonEn 245300 346800 Valspar 46900 117100 Wrigley 111000 267200