A random sample of 15 adults living in a small town are selected to estimate the proportion of voters favoring a certain candidate for mayor. Each individual was also asked if he or she was a college graduate. Byletting $Y$ and $N$ designate the responses of "yes" and "no" to the education question, the following sequence was obtained:
$$
N N N N Y Y N Y Y N Y \mathrm{~A}^{\prime \prime} N N N
$$
Use the runs test at the 0.1 level of significance to determine if the sequence supports the contention that the sample was selected at random.