1. A fourth grade teacher gives homework every night in both mathematics and language arts. The time to complete the mathematics homework has a mean of 10 minutes and a standard deviation of 3 minutes. The time to complete the language arts assignment has a mean of 12 minutes and a standard deviation of 4 minutes. The time to complete the mathematics and the time to complete the language arts homework has a correlation ρ = -0.75. The standard deviation of the time to complete the entire homework assignment is
A. 25 minutes.
B. 5 minutes.
C. 3 minutes.
2. I toss a thumbtack 60 times and it lands point up on 35 of the tosses. The approximate probability of landing point up is
A. 35.
B. 0.35.
C. 0.58.
3. A game consists of drawing three cards at random from a deck of playing cards. You win $3 for each red card that is drawn. It costs $2 to play. For one play of this game, the sample space S for the net amount you win (after deducting the cost of play) is
A. S = {$0, $1, $2, $3}
B. S = {$0, $3, $6, $9}
C. S = {-$2, $1, $4, $7}