Question 1086483
<font color="black" face="times" size="3">We will use this formula
n = ( (z*sigma)/E )^2


The variables are
n = sample size
z = critical value
sigma = population standard deviation
E = margin of error
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Use a table or calculator to find that
Critical value = z = 1.28 (at 80% confidence)


In this case, we're given
sigma = 150
E = 10


Plug those values into the formula to get:
n = ( (z*sigma)/E )^2
n = ( (1.28*150)/10 )^2
n = ( 192/10 )^2
n = ( 19.2 )^2
n = 368.64
n = 369 ... round up to the nearest whole number


Final answer is choice B) 369</font>