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In: Statistics and Probability

Find a 99% confidence interval for a mean of 220. Does the test stastic lie in...

Find a 99% confidence interval for a mean of 220. Does the test stastic lie in the confidence interval?

Standard Deviation: 74.

Expert Solution

the formula for the confidence interval is :

where = sample mean = 220 ; = standard deviation=74 ;

= standard normal variate at ;(If the population standard deviation is unknown and we need to calculated sample standard deviation (), then t statistic will be used instead of z, with degrees of freedom n-1, and same as z)

Here, = level of significance = (100-99)% = 1%= 0.01.

So = = 2.576 (from standard normal table);

= sample size = 180. So, The required interval is -

.

Feel free to ask anything, any query related to this question .Thank you so much!

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orchestra answered 1 year ago

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