When marginal revenue equals marginal cost, profit is at its highest. why?

Your mother's well-diversified portfolio has an expected return of 12.0% and a beta of 1.20. she is in the process of buying 100 shares of safety corp. at $10 a share and adding it to her portfolio. safety has an expected return of 15.0% and a beta of 2.00. the total value of your current portfolio is $9,000. what will the expected return and beta on the portfolio be after the purchase of the safety stock?

The following information is needed to reconcile the cash balance for gourmet catering services. * a deposit of $5,600 is in transit. * outstanding checks total $1,000. * the book balance is $6,400 at february 28, 2019. * the bookkeeper recorded a $1,800 check as $17,200 in payment of the current month's rent. * the bank balance at february 28, 2019 was $17,410. * a deposit of $400 was credited by the bank for $4,000. * a customer's check for $3,300 was returned for nonsufficient funds. * the bank service charge is $90. what was the adjusted book balance?

What can be concluded from the data about the reliability and validity of the thermometers