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## Statistics and probability

### Course: Statistics and probability>Unit 11

Lesson 1: Introduction to confidence intervals

# Confidence interval simulation

Confidence interval simulation.

## Want to join the conversation?

• Is the simulation software available to students? If so, can you share a link? Thanks -
• does anyone have a link to the simulation? The one I found doesn't work at all
• Can we calculate the confidence level, even when the distribution of the proportions is not normal ( there are fewer than 10 expected successes) ?
• I'm reading a scientific article with results formatted as follows
mean = 7·7 (SD = 5·4), placebo 9·0 (6·0); effect size -1·2, (95% CI -2·3, -0·1), p = 0·037)
How do I interpret this?
• why is standard error of sample proportion and confidence interval useful?
• The standard error (otherwise called as confidence interval) of sample proportion is used to estimate population proportion. If you find the 99% confidence interval (0.45 to 0.66 for example) from a sample proportion, it says that the population proportion is between that interval (0.45 to 0.66).
(1 vote)
• Is there a notes version of this topic some where? I cant follow along well enough to take notes on this, and if there isnt one, could you please make one?
• This is not correct. The size of the horizontal bars should change depending on the phat. Is that not how we derived SE in the previous video (erroneously I feel).
Why are the horizionatal confidence bars same size -- looks like it was based on the std.dev of population which we claimed in the previous video we do not know.
(1 vote)
• The intervals are not the same length. Take a screenshot of the video when the intervals are displayed and measure a few of them and you'll see they vary. Not by much, but look at it this way: 0.6 * 0.4 = 0.24, while 0.5 * 0.5 = 0.25. That's not much of a difference, especially after you plug into the standard error formula.