A group of researchers was interested in the effect of music on the behavior of dogs. Specifically, they wanted to measure the effect of classical music on sleepiness as an indication of dogs’ mental relaxation. They conducted the following study on a group of $400$ Jack Russell Terriers.
Every day for $4$ months, the researchers would play Beethoven’s Moonlight Sonata for $1$ hour occurring randomly between $9\text{ a.m.}$ and $12\text{ p.m.}$ During the entire $3$ hours, observers would record the times in which each dog was sleeping. By the end of the $4$ months, the researchers calculated and compared the percentage of time each dog spent sleeping during each of two conditions: while the music was playing and while it wasn’t.
**What type of statistical study did the researchers use?**
[[☃ radio 1]]
**Is the study appropriate for the statistical questions it's supposed to answer?**
Mark the most suitable choice.
[[☃ radio 2]]