Well, there are two solutions.
Add both sides by 15.75 then from here, you can use quadratic formula.
So your answer should be x = -2.44949 or 2.44949.
Answer:
Now we can calculate the p value. Since is a bilateral test the p value would be:

Since the p value is lower than the significance level of 0.05 we have enough evidence to conclude that the true proportion of residents favored annexation is higher than 0.72 or 72%
Step-by-step explanation:
Information given
n=900 represent the random sample selected
estimated proportion of residents favored annexation
is the value that we want to test
represent the significance level
z would represent the statistic
represent the p value
Hypothesis to test
The political strategist wants to test the claim that the percentage of residents who favor annexation is above 72%.:
Null hypothesis:
Alternative hypothesis:
The statistic for this case is given by:
(1)
Replacing the data given we got:
Now we can calculate the p value. Since is a bilateral test the p value would be:

Since the p value is lower than the significance level of 0.05 we have enough evidence to conclude that the true proportion of residents favored annexation is higher than 0.72 or 72%
0.375 is the answer because there are 3 0's in COLORADO and 8 letter's in total. The fraction part would be 3/8 and in decimals it is 0.375.
I think that £3250/month is better because why would you want to spend £4000 when you can spend £3250.