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In: Statistics and Probability

The amount of study time a student gets in a week has a mean of 7.25...

The amount of study time a student gets in a week has a mean of 7.25 hours with a standard deviation of 48 minutes. If a sample of 68 students is randomly selected, what is the probability the average amount of study time in a week for these students is less than 7 hours?

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Expert Solution

Solution :

Given that,

mean = = 7.25 hours

standard deviation = = 48=0.8hours

n = 68

= 7.25

=  / n = 0.8/ 68=0.097

P( <7 ) = P[( - ) / < (7-7.25) /0.097 ]

= P(z <-2.58 )

Using z table  

= 0.0049   

probability= 0.0049

orchestra answered 2 years ago
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