I am a big shot research scientist at Washington University where I am using 2ebrafish to study neuronal migration. My graduate students measured 40 fish and found that the mean length of the fish sampled was 3.7 cm with a standard deviation of 0.5 cm.

Question

I am a big shot research scientist at Washington University where I am using 2ebrafish to study neuronal migration. My graduate students measured 40 fish and found that the mean length of the fish sampled was 3.7 cm with a standard deviation of 0.5 cm.

Construct a 95% confidence interval for the population mean
Our competitor's lab has published that their fish have an average length of 4 cm Is our data consistent with our competitor's data? Why or Why not?

Answer 1

95% = mean ± 1.96 SEm

SEm = SD/√n

Where does 4 cm fit in this distribution?