Answer:
The probability is [tex]P(\= X > x ) = 0.78814[/tex]
Step-by-step explanation:
From the question we are given that
The population mean is [tex]\mu = 149[/tex]
The standard deviation is [tex]\sigma = 14[/tex]
The random number [tex]x = 147.81[/tex]
The sample size is [tex]n = 88[/tex]
The probability that the sample mean would be greater than [tex]P(\= X > x ) = P( \frac{ \= x - \mu }{\sigma_{\= x} } > \frac{ x - \mu }{\sigma_{\= x} } )[/tex]
Generally the z- score of this normal distribution is mathematically represented as
[tex]Z = \frac{ \= x - \mu }{\sigma_{\= x} }[/tex]
Now
[tex]\sigma_{\= x } = \frac{\sigma }{\sqrt{n} }[/tex]
substituting values
[tex]\sigma_{\= x } = \frac{14 }{\sqrt{88} }[/tex]
[tex]\sigma_{\= x } = 1.492[/tex]
Which implies that
[tex]P(\= X > x ) = P( Z > \frac{ 147.81 - 149 }{ 1.492} )[/tex]
[tex]P(\= X > x ) = P( Z > -0.80 )[/tex]
Now from the z-table the probability is found to be
[tex]P(\= X > x ) = 0.78814[/tex]
