Hi (A) At least one of them registers a game-high 185 points. Using TI or similarly an inexpensive calculator like an Casio fx-115 ES plus Bea: µ = 170 and σ = 5 Ana: µ = 175 and σ = 10 P(Bea OR Anna have 185) = .0009 + .024 = .0249 (B) Ana and Bea both receive scores of between 168 and 173. B(both between 168 and 173) = (.38)(.18) Wish You the Best in your Studies.
P(Ana above 185) = P_normal (µ = 175; σ = 10; above 185) = 0.1587 (use your calculator or any tool which you like). P(Bea above 185) = P_normal](µ = 170; σ = 5; above 185) = 0.0013. P(Ana OR Bea above 185) = P(Ana above 185) + P(Bea above 185) - P(Ana above 185)*P(Bea above 185) = = 0.1587 + 0.0013 - 0.1587 *0.0013 = 0.1598. ANSWER to question A)