Question 1133950
The mean is 5.24/7=0.749
sd=0.404
CI percentage not given.  Will use 95%, although with mercury, one might want a higher confidence.
t 0.975,df=6 is 2.447
half-interval is t*s/sqrt(n)=2.447*0.404/sqrt(7)=0.374
95%CI is (0.375, 1.123) units ppm