Multiple choice

Professor Buckingham, a chemist and teacher at a community college, is organising his graduated cylinders in the hopes of keeping his office tidy and setting a good example for his students. He has beakers with diameters, in inches, of $\displaystyle\frac{1}{2}, \frac{3}{4}, \frac{4}{5}, 1$ and $\displaystyle\frac{5}{4}$. With his original five cylinders, professor Buckingham realises that he is missing a cylinder necessary for his upcoming lab demonstration for Thursday's class. He remembers that the cylinder he needs when added to the original five, will create a median diameter value of $\displaystyle\frac{9}{10}$ for the set of six total cylinders. He also knows that the measure of the sixth cylinder will exceed the value of the range of the current five cylinders by a width of anywhere from $\displaystyle\frac{1}{4}$ inches to $\displaystyle\frac{1}{2}$ inches, inclusive. Based on the data, what is one possible value of y, the diameter of this missing sixth cylinder?

  1. $1 \leq y\leq 1.25$
  2. $2 \leq y\leq 2.25$
  3. $3 \leq y\leq 3.25$
  4. $4 \leq y\leq 4.25$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The current range is 1.25-0.5=0.75 inches. The sixth diameter must therefore be between 1 and 1.25 inches, and y=1 also gives a median of 0.9 for the six values.

AI explanation

The current range of the five cylinders is the maximum diameter of 1.25 inches minus the minimum diameter of 0.5 inches, which equals 0.75 inches. Adding a quarter to half an inch to this range means the new cylinder's diameter must be between 1.0 and 1.25 inches. To maintain a median of 0.9 for six cylinders, this fifth largest cylinder must simply be greater than the original fourth value of 0.8, which is satisfied by the range of 1.0 to 1.25. Therefore, the possible value of y is between 1 and 1.25.