A manufacturer knows that their items have a normally distributed lifespan, with a mean of 12.3 years, and standard deviation of
0.8 years. If you randomly purchase one item, what is the probability it will last longer than 14 years
1 answer:
Answer:
probability of lasting longer = 1.7%
Step-by-step explanation:
We are given:
x' = 14 years
μ = 12.3 years
s = 0.8 years
Thus, let's use the formula for the Z-score value which is;
z = (x' - μ)/s
Thus;
z = (14 - 12.3)/0.8
z = 2.125
From the z-distribution table attached, the p-value is ;
P(x' > 2.125) = 1 - 0.983 = 0.017 = 1.7%
Thus,probability of lasting longer = 1.7%
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Answer:
a) P(X<50)=0.9827
b) P(X>47)=0.4321
c) P(-1.5<z<1.5)=0.8664
Step-by-step explanation:
We will calculate the probability based on a random sample of one moped out of the population, normally distributed with mean 46.7 and standard deviation 1.75.
a) This means we have to calculate P(x<50).
We will calculate the z-score and then calculate the probability accordign to the standard normal distribution:
b) We have to calculatee P(x>47).
We will calculate the z-score and then calculate the probability accordign to the standard normal distribution:
c) If the value differs 1.5 standard deviations from the mean value, we have a z-score of z=1.5
So the probability that maximum speed differs from the mean value by at most 1.5 standard deviations is P(-1.5<z<1.5):