In a statistics class, the standard deviation of the heights of all students was 4.24.2 inches. the standard deviation of the heights of males was 3.53.5 inches and the standard deviation of females was 3.13.1 inches. why is the standard deviation of the entire class more than the standard deviation of the males and females considered separately?

Suppose i flip two identical coins. what is the probability that i get one head and one tail?

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.

Julie was able to walk 16 km through the zoo in 6 hours. how long will it take her to walk 24 km through the zoo?