SOLUTION: Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.† Suppose a small group of 12 Allen's hummingbirds has been under study in Arizona. The average we

Algebra ->  Probability-and-statistics -> SOLUTION: Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.† Suppose a small group of 12 Allen's hummingbirds has been under study in Arizona. The average we      Log On


   

Question 860960: Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.† Suppose a small group of 12 Allen's hummingbirds has been under study in Arizona. The average weight for these birds is x = 3.15 grams. Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with σ = 0.20 gram.
(a) Find an 80% confidence interval for the average weights of Allen's hummingbirds in the study region. (Round your answers to two decimal places.)

A.lower limit
B.upper limit
c. margin of error
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

ME = 1.2816%28.20%2Fsqrt%2812%29%29= .07 (2 decimal points

CI: μ-ME < u <  μ + ME

CI: 3.15g-ME < u <  3.15g + ME

CI: 3.08g < u < 3.22g

CI	z -value

80%     z= 1.2816

90%	z =1.645

92%	z = 1.751

95%	z = 1.96

98%	z = 2.326

99%	z = 2.576