If a sample proportion is 0.55, which of the following could be a 90% confidence interval for the population proportion? Select all that apply. (a) Lower bound: 0.50; Upper bound: 0.60 (b) Lower bound: 0.53; Upper bound: 0.59 (c) Lower bound: 0.52; Upper bound: 0.58 (d) Lower bound: 0.60; Upper bound: 0.70 (e) Lower bound: 0.45; Upper bound: 0.60​

The correct options are a and c.

Step-by-step explanation:

Confidence interval:

A confidence interval is given by the sample proportion plus/minus the margin of error. This means that the confidence interval is symmetric, that is, the difference between the upper bound and the sample proportion has to be the same as the difference between the sample proportion and the lower bound.

Sample proportion is 0.55

So options for the confidence interval are:

Lower bound - upper bound

0.54 - 0.56

0.53 - 0.57(which means that option b is wrong)

0.52 - 0.58(which means that option c is right)

...

0.5 - 0.6(which means that option a is right).

The correct options are a and c.