The mean amount spent by a family of four on food per month is $500 with a standard deviation of $75. assuming that the food costs are normally distributed, what is the probability that a family spends less than $410 per month? 0.2158 0.8750 0.0362 0.1151
Question
Answer:
Are you familiar with z-scores? According to the definition,
(given numerical value) - (mean)
z = ---------------------------------------------
standard deviation
Thus, with the given numerical value equal to 410 and the std. dev. equal to 75, the corresponding z-score is
410-500 -90
z = --------------------- = --------------- = -1.2
75 75
Use a table of z-scores to determine the area under the standard normal curve to the left of z = -1.2. Your result is the probability that a given family chosen at random spends less than $410 per month.
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