9514 1404 393
Answer:
y = 3.02x^3 -5.36x^2 +5.68x +8.66
Step-by-step explanation:
Your graphing calculator (or other regression tool) can solve this about as quickly as you can enter the numbers. If you have a number of regression formulas to work out, it is a good idea to become familiar with at least one tool for doing so.
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If you're trying to do this by hand, the x- and y-values give you 4 equations in the 4 unknown coefficients.
a·1^3 +b·1^2 +c·1 +d = 12
a·3^3 +b·3^2 +c·3 +d = 59
a·6^3 +b·6^2 +c·6 +d = 502
a·8^3 +b·8^2 +c·8 +d = 1257
Solving this by elimination, substitution, or matrix methods is tedious, but not impossible. Calculators and web sites can help. The solutions are a = 317/105, b = -75/14, c = 1193/210, d = 303/35. Approximations to these values are shown above.
Answer:
110 words in 5 min, 220 words in 10 min
Step-by-step explanation:
y = mx (there is no intercept because you can't type anything in 0 minutes)
66 = 3m
m = 22
y = 22x
5 minutes:
y = 22(5) = 110 words
10 minutes:
y = 22(10) = 220 words
Answer: D) Increase the sample size and decrease the confidence level.
Step-by-step explanation:
A reduced interval width means that the data is more accurate. This can only be achieved if the sample size is increased because a larger sample size is able to capture more of the characteristics of the variables being tested.
A smaller confidence interval will also lead to a reduced interval width because it means that the chances of the prediction being correct have increased.
Answer:
9. It seems he was inactive/taking a break, as the line is completely straight.
I'm not sure about the others, but I hope that helps!
Step-by-step explanation: