The temperature in Greenland was -12°. For 4 hours the temperature rose 3º every hour.
What was the temperature after 4 hours ?

I’m stuck on this i don’t understand.

The lengths of nails produced in a factory are normally distributed with a mean of 4.91 centimeters and a standard deviation of 0.05 centimeters. find the two lengths that separate the top 4% and the bottom 4%. these lengths could serve as limits used to identify which nails should be rejected. round your answer to the nearest hundredth, if necessary.

Acd that is originally priced at $15.85 red-tagged for the sale. what is the sale price of the cd