Unknown mean μ yielded x¯
x
¯
= 123 and s = 28. Assume σ
σ
= 25. Construct a 90% confidence interval for

The answer is below

Explanation:

The question is not complete, but I will solve a similar question. The question goes as:

A random sample of n measurements was selected from a population with unknown mean µ and known standard deviation σ. Calculate a 90% confidence interval for n = 49, ¯ x = 28, σ = 28

Solution:

A confidence interval is a range of numbers that contains a population parameter.

C = 90% = 0.9

α = 1 - C = 1 - 0.9 = 0.1

α/2 = 0.1/2 = 0.05

The z score of α/2 is the same as the z score 0.45 (0.5 - 0.05) which is equal to 1.65. Hence, the margin of error E is:

The confidence interval =

The 90% confidence is between 21.4 and 34.6.

man vs. nature - first choice

when alex falls for the charming new boy at school, cole -- a handsome, funny, sports star who adores her - she can't believe she's finally found her soul who truly loves and understands her.  

at first, alex is blissfully happy. sure, cole seems a little jealous of her relationship with her close friend zack, but what guy would want his girlfriend spending all her time with another boy? as the months pass, though, alex can no longer ignore cole's small put-downs, pinches, or increasingly violent threats.  

as alex struggles to come to terms with the sweet boyfriend she fell in love with and the boyfriend whose "love" she no longer recognizes, she is forced to choose -- between her "true love" and herself.

explanation: