Assume that the number of watches produced every hour is normally distributed with a mean of 500 and a standard deviation of 100. what is the probability that in a randomly selected hour the number of watches produced is greater than 500

To evaluate the probability that in a randomly selected hour the number of watches produced is greater than 500 we proceed as follows:
z=(x-μ)/σ
where:
x=500
μ=500
σ=100
thus
z=(500-500)/200=0

Thus:
P(x>500)=1-P(x<500)=1-P(z<0)=1-0.5=0.5

Answer: 0.5~50%

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JeanaShupp JeanaShupp · Answer 2 · 2020-03-27T14:26:02+01:00

Answer: 0.5

Step-by-step explanation:

Given : The number of watches produced every hour is normally distributed with a mean of 500 and a standard deviation of 100.

i.e. [tex]\mu = 500\text{ and } \sigma= 100[/tex]

Let x be the number of watches produced every hour.

Then, the probability that in a randomly selected hour the number of watches produced is greater than 500 will be :

[tex]P(x>500)=1-P(x\leq500)\\\\=1-P(\dfrac{x-\mu}{\sigma}\leq\dfrac{500-500}{100})\\\\=1-P(z\leq0)\ \ [\because\ z=\dfrac{x-\mu}{\sigma}]\\\\=1-0.5\ \ [\text{ By z-table}]\\\\=1-0.5=0.5[/tex]

Hence, the probability that in a randomly selected hour the number of watches produced is greater than 500 =0.5.