Indirect Measures Printer Friendly Version
During our first indirect measurement lab, we used the fact that the following ratios were equivalent when a marble was dropped randomly on a target paper filled with circles.

Refer to the following information for the next six questions.

Show below is a sample target from a group of students large circle lab. Note that the image is NOT TO SCALE.

 How many hits struck within a circle? Remember that a strike hitting the perimeter of a circle does NOT count.

 How many hits struck within the blue rectangular area? Remember that a strike hitting the perimeter of the rectangle does NOT count.

 What percentage of the total area of the blue rectangular area is covered by the six yellow circles?

 If the blue rectangle measures 20 cm by 15 cm, what is the area of one circle?

 What is the radius on one circle?

 If the actual radius of one circle was 2.50 cm, what percent error did the students obtain on their lab?

Refer to the following information for the next three questions.

Another group of students collected the following data using the same target. Once again, note that the image is NOT TO SCALE although both images are presented at the same magnification.

If this group dropped the marble 50 more times, would you expect their percent error to better or worse than the first group's?

 If there were 98 circle hits out of a total of 226 rectangle hits, what was this group's percent error?

Refer to the following information for the next three questions.

During our second indirect measurement lab, we used the ratio

Shown below is a sample of the data obtained by a third group of students for our second lab.

 How many circle hits did this group get?

 How many square hits?

 What was the group's percent error?