Answer: Few phrases make me cringe the way I do when I hear, “Ours is not to reason why; just invert and multiply.” A student’s job in math class is to reason, and a teacher’s job is to help the students see that math makes sense. Understanding division of fractions is complicated, bringing together many ideas that build up to a method that makes sense, especially in the tricky case of a fraction divided by a fraction. Liping Ma writes about research asking teachers to explain what it means to divide by a fraction. Most U.S. teachers were startled to find how difficult this was for them. What if we start with the simpler case of a whole number divided by a fraction?
We know the circle has its center at the origin, 0,0, and the point -4,-2 is on the circle, is just the distance from the center to a point on it, thus
It is given that the sample size is 17.
So degrees of freedom is 16.
The confidence level is 80%.
Use the t table or a tool to find the critical t value as below:
The one tail t value for 80 percent confidence is 0.865 using t table.
So the critical value is 0.865.