Sara spent half of her allowance going to the movies. She washed the family car and earned 9 dollars. What is her weekly allowance is she ended with 12 dollars
(Two steps equations)

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.