6. A hotel puts 4 pillows in each of its, r, rooms and stores
another 100 pillows in case guests want more. If the hotel
has 452 pillows total, how many rooms, r, are in the hotel.
Identify the correct equation and value for r.
a) 4r – 452 = 100
b) 4r + 100 = 452
I c) r= 138
d) p = 88
e) 4(r + 100) = 452

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?