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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):
Answer:
x = - , x = 3
Step-by-step explanation:
Given
(4x - 5)² = 49 ( take the square root of both sides )
4x - 5 = ± = ± 7 ( add 5 to both sides )
4x = 5 ± 7, thus
4x = 5 - 7 = - 2 ( divide both sides by 4 )
x = = -
or
4x = 5 + 7 = 12 ( divide both sides by 4 )
x = 3
As a check
Substitute these values into the left side of the equation and if equal to the right side then they are the solutions.
x = -
left side = (- 2 - 5)² = (- 7)² = 49 = right side ⇒ solution
x = 3
left side = (12 - 5)² = 7² = 49 = right side ⇒ solution