150 students is 60 kg the mean of body is 70 kg withstandard deviation of 10 kg and mean weight of girls is 55 kg with standard deviation of 15kg.calculate the number of boys and the combined standard deviation. Also find whether the coefficient of deviation is hired for girls or boys.

Answer 1

Please proof read
does body mean boys?
what is 60 kg ?
who got hired for what?

http://davidmlane.com/hyperstat/z_table.html

Answer 2

9000=70x+8250-55x
Boys 50
Girls 100

Answer 3

1. The probability that a freshman entering Bahir Dar University will survive first semester is
0.89. Assuming this pattern remain unchanged over the subsequent years, what is the probability
that among 100 randomly selected freshmen students in first semester,
a) None will survive? b) Exactly 97 will survive c) At least three will survive�

Answer 4

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