For 1940 to 1980, the daily water use W (in billions of gallons) in the United States followed the
quadratic model
W = 0.050t2 + 6.109t + 130.727
where t = 0 represents 1940. Suppose this model had
been used to predict the water use for 1980 through 1995.
The actual use in 1995 was 402 billion gallons. Was this
less or more than the predicted consumption for 1995?
Explain.

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?

Can some one explain how to slove specifically, what is the value of x? 0.9(x+1.4)-2.3+0.1x=1.6 enter the answer as a decimal in the box. x= ?

Which radical expression is a rational number? a. √ 360 b. √ 644 c. √ 225 d. √ 122