A random sample of 93 observations produced a mean of x=25.5 and a standard deviation of 2.8.
a. find a 95% confidence interval for u (mean?)
b. find a 90% confidence interval for u (mean?)
c. find a 99% confidence interval for u (mean?)
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A random sample of n=100 observations is selected from a population with mean of 29 and sandard deviation of 21. Approximate the probabilities shown below
a. P(x=(mean) greater than or equal to 28)
b. P(22.1 less than or equal to x =(mean) less than or equal to 26.8)
c. P(x=(mean)less than or equal to 28.2)
d. P (x=(mean) greater than or equal to 27.0)