Formula:
CI90 = p + or - (1.645)[√(pq/n)]
...where p = x/n, q = 1 - p, and n = sample size.
Note: + or - 1.645 represents 90% confidence interval.
p = .659
q = 1 - p = .341
n = 1026
I let you take it from here.
Politicians are interested in knowing the opinions of their constituents on important issues. One administrative assistant to a senator claims that more than 63% of adult women favor stricter gun laws. A recent telephone survey of 1026 adult women by IBR Polls found that 65.9% of adult women favored stricter gun laws.
The 90% confidence interval is: ( % , %)
Enter each number as a percent rounded to tenths of a percent.
2 answers
Would the interval be 63.5 to 68.3?