You want to build a 95% confidence interval for the average iq of all statistics instructors.
you randomly select 20 statistics instructors and measure their iq's. you get a sample average of 143. it is known that the population of iq's is normally distributed with a population standard deviation of 16.

what is the upper confidence limit (ucl) of you confidence interval?

round your answer to the nearest integer.

Upper limit 150

Lower bond 136

Step-by-step explanation:

Hello!

The study variable is:

X: measurement of IQ of a statistic instructor.

This variable has a normal distribution:

X~N(μ; σ²)

And the population standard deviation is known σ= 16

You need to construct a confidence interval for the population mean, for this, since the variable has a normal distribution and the population variance is known, the statistic to use is the standard normal

Z= X[bar] - μ ~N(0;1)

σ/√n

The formula for the interval is:

X[bar] ± *

Where

X[bar] is the sample mean

is the value under the Z distribution for the corresponding confidence level.

S is the population standard deviation. (should be sigma but it doesn't recognize the symbol)

[143 ± 1.96 * ]

[135,988; 150. 012] ≅ [136; 150]

I hope it helps!

this may not be at all, but i use the same website you're using for school, and if i'm stuck doing one of these i try to look for it on the section.

answer: (-6,3)

step-by-step explanation: