Answer:
1.1125
Step-by-step explanation:
the relative weight of the stocks that you are selling is $100,000/$4,000,000 = 0.025 = 2.5% of the portfolio
this means that their effect on the portfolio's beta was 0.9 x 0.025 = 0.0225
the new stocks that you want to purchase have a beta of 1.4 and their relative effect on the portfolio's beta will be 1.4 x 0.025 = 0.035
the difference between both stocks = 0.035 - 0.0225 = 0.0125
that means that the portfolio's new beta = 1.1 + 0.0125 = 1.1125