Heights of adult males are known to have a normal distribution. a researcher claims to have randomly selected adult males and measured their heights with the resulting relative frequency distribution as shown here. identify two major flaws with these results. height (cm) relative frequency 130 dash –144 22 22% 145 dash –159 25 25% 160 dash –174 21 21% 175 dash –189 26 26% 190 dash –204 28 28%

Consider a graph for the equation y= -3x+4. what is the y intercept? a) 4 b) -4 c) 3 d) -3

Which fraction below is equivalent to 10/12?

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60