a) How large a sample must be drawn so that a 90% confidence interval for will have a margin of error equal to 3.4? Round the critical value to no less than three decimal places. Round the sample size up to the nearest integer. A sample size of is needed to be drawn in order to obtain a confidence interval with a margin of error equal to 3.4 .

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

The equation of a circle is (x + 4)2 + (y + 6)2 = 16. determine the length of the radius. 10 4 16 8 my flower basket delivers flowers within a 20 mile radius of their store. if this area is represented graphically, with my flower basket located at (5, 2), what is the equation that represents the delivery area? (x - 2)2 + (y - 5)2 = 20 (x - 5)2 + (y - 2)2 = 20 (x + 5)2 + (y + 2)2 = 400 (x - 5)2 + (y - 2)2 = 400

The frequency table shows a set of data collected by a doctor for adult patients who were diagnosed with a strain of influenza. patients with influenza age range number of sick patients 25 to 29 30 to 34 35 to 39 40 to 45 which dot plot could represent the same data as the frequency table? patients with flu