# Express the confidence interval using the indicated format?

##
- interval (0.432,0.52) in form of
#\hat{p}\pmE#
- interval (0.688,0.724) in form of
#\hat{p}\pmE#

- interval (0.432,0.52) in form of
#\hat{p}\pmE# - interval (0.688,0.724) in form of
#\hat{p}\pmE#

##### 1 Answer

Aug 3, 2017

- 0.476 +/- 0.044
- 0.706 +/- 0.018

#### Explanation:

The Z and t-tests are based on a normal distribution assumption. The intervals given do not indicate any particular confidence level, so they are just the bounds of the “accepted” confidence interval. Thus, the intervals are the range of probabilities, so the error is just +/-½ of the range.

This gives us a form of

1. 0.476 +/- 0.044

2. 0.706 +/- 0.018

See also:

http://stattrek.com/probability-distributions/t-distribution.aspx