Jamal needs to create a nitric acid solution which is less than 15% nitric acid. he begins with 12 fluid ounces of a 20% nitric acid solution in water and he adds 8 fluid ounces of water. does he need to add more water?

Solve the equation using the given values: x= -2.5; y= -7.51. 2xy + 2x²

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Aladder that is 20ft long is leaning against the side of a building. if the angle formed between the ladder and the ground is 75 degrees how far is the bottom of the from the base of the building?