I Need help please I only have 10 minutes

One month, a music site observed that 60% of the people who downloaded songs from its site downloaded q sam's latest single. the equation below represents this information, where x represents the total number of people who ddownloaded songs from the site that month: x = 0.6x + 384 how many people who downloaded songs from the site that month downloaded q sam's latest single?

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6