C= Colorado B= Boston
C + B = 464
C = 1.2B
Substitute the known value of C from the second equation into the first
C + B = 464
(1.2B) + B = 464
2.2B = 464
Divide each side by 2.2
B = 210.9, rounded to 211 (it's asking for days, not partial days, so round)
If Boston has 211 days of sunshine , then Colorado Springs has 1.2 times that amount. 211 * 1.2 = 253.2 (rounded to 253)
Verification
211 + 253 = 464
1.20 - .90 = .30
.30 / 5 = .06 (Same as 30 / 5)
The price of a pound of oranges went up by 6 cents per year.
X intercept: (- 1/7, 0)
Y intercept: (0, 1/4)
The confidence interval is

We first find p, our sample proportion. 118/200 = 0.59.
Next we find the z-score associated with this level of confidence:
Convert 98% to a decimal: 98% = 98/100 = 0.98
Subtract from 1: 1-0.98 = 0.02
Divide by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value is associated with a z-score of 2.33.
The margin of error (ME) is given by

This gives us the confidence interval