A study was designed to estimate the true mean amount of radioactive element in lichen specimens. A sample of 9 lichen specimens were investigated, leading to the sample mean and standard deviation being 0.009 and 0.005 microcurie per milliliter, respectively. (a) Based on the sample information, construct a 99% confidence interval for the true mean amount of radioactive lelement. (b) What are underlying assumptions are required for the confidence interval in part(a) being valid

x =-.20752

step-by-step explanation:

4^(x+2)=12

4^(x+2)=12

take the log base 4 on each side

log 4 (4^(x+2) = log 4(12)

we know log b(a^y) = y log b (a)

(x+2) log 4(4) = log 4 (12)

x+2 = log 4 (12)

we know   logb c = loga c/loga b

we want to convert to base 10   so a = 10

by default, we do not write the 10   c = 4   and b = 10

log4 10 = log 12/log 4

log4 10 = log 12/ log 4

x+2 = log 12/ log 4

subtract 2 from each side

x +2 -2 = log 12/ log 4 -2

x = 1.79248125 -2

x =-.20752

493 would be the correct answer

step-by-step explanation: