Answer:
(B) The correct interpretation of this interval is that 90% of the students in the population should have their scores improve by between 72.3 and 91.4 points.
Step-by-step explanation:
Confidence interval is the range the true values fall in under a given <em>confidence level</em>.
Confidence level states the probability that a random chosen sample performs the surveyed characteristic in the range of confidence interval. Thus,
90% confidence interval means that there is 90% probability that the statistic (in this case SAT score improvement) of a member of the population falls in the confidence interval.
A - 2 1/2 = 1 1/2
Solve for A by adding 2 1/2 to both sides:
A = 1 1/2 + 2 1/2
A = 4
The answer is c. A = 4
Check: 4 - 2 1/2 = 1 1/2
An equation with a difference of 6 would be 12-6=6
The answer to the question is 25t+26