Answer:
Step-by-step explanation:
Hello There!
Once again we need to isolate the variable using inverse operations
to get rid of the -8.2 we add 8.2 to each side
-8.2+8.2 cancels out
-9.7+8.2=-1.5
now we have
-1.2z>-1.5
now we wan to get rid of the -1.2
to do so we want to divide each side by -1.2
Remember we have to flip the inequality sign because we're dividing by a negative number
we're left with
z<1.25
Answer:
So the answer for this case would be n=247 rounded up to the nearest integer
Step-by-step explanation:
We know that the standard deviation is :
represent the deviation
The margin of error is given by this formula:
(a)
And on this case we have that ME =25 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
The critical value for 95% of confidence interval now can be founded using the normal distribution and the critical value would be , replacing into formula (b) we got:
So the answer for this case would be n=247 rounded up to the nearest integer