Question

Sample mean, x ̅ = 2.26 nM, sample standard deviation, s = 1.18 nM, and sample size, n = 12.

in this area there is a natural amount of arsenic in snow, and researchers have established that the natural level is 1.5 nM. State the null hypothesis and the alternative hypothesis that should be used to determine if the level of arsenic concentration was (at that time) higher than the natural level of 1.5 nM.
The sample size is rather small. What assumption is needed so that the normality criteria are satisfied?  

The sample size is rather small. What assumption is needed so that the normality criteria are satisfied?

Calculate the value of the test-statistic, t, using t=x-μ/s n

Use the test-statistic and tcdf(Low,High,df) to find the p-value for this sample.

Answer 1

Given that X= 2:26 AM &=1.18 M R=12 u- 1,5 AM Hie u 1.5 nm t= T-M stro 12 (2.26-1:5) 1-18 t 2.231 P value is 0.0237