The birth weights (in kilograms) of 5 elephants, selected randomly, are 133, 120, 97, 106, 124 (Source: www.elephant.se). Below
are the summary statistics of the data and output from the analysis testing if the true average birth weight of the elephants is 100 kg. min Q1 median Q3 max mean sd n missing
97 106 120 124 133 116 14.40 486 5 0
t = 2.4837, df = 4, p-value = 0.06794
alternative hypothesis: true mean is not equal to 100 95 percent confidence interval:
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What is the correct calculation of a 95% confidence interval for the true average birth weight of elephant?
(i) 116± 1.96 x 14.4
(ii) 116 ± 1.96 x 14.4/15
(iii)116 ±1.96 x 14.4/14
(iv) 116 ± 2.4837 x 14.4
(v) 116 ±2.4837 x 14.4/15
(vi) 116 ± 2.4837 14.4/74
(vii) 116 ± 2.78 x 14.4
(viii) 116 ± 2.78 x 14.4√5
(ix) 116 ±2.78 x 14.4√4
If an integer is chosen between 1 and 50 inclusive, you have 50 numbers total to deal with, so 50 is in the denominator of our ratio (fraction). All the numbers divisible by 3 in that interval total 16 numbers. So the ratio would be 16/50 for a percentage of 32%
When adding negative numbers if the are both negative then you add them. When you have a negative and a positive you subtract. In this problem they just took out the plus sign.
