Respuesta :
Answer:
a) 0.274 is the probability that the deli will sell up to 7 newspapers in a given hour.
b) 0.345 is the probability that the deli will sell 12 or more newspapers in a given hour.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 10 per hour
Standard Deviation, σ = 5 per hour
Formula:
[tex]z_{score} = \displaystyle\frac{x-\mu}{\sigma}[/tex]
a) P(deli will sell up to 7 newspapers in a given hour)
P(x < 7)
[tex]P( x < 7) = P( z < \displaystyle\frac{7 - 10}{5}) = P(z < -0.6)[/tex]
Calculation the value from standard normal z table, we have,
[tex]P(x <7) = 0.274 = 27.4\%[/tex]
0.274 is the probability that the deli will sell up to 7 newspapers in a given hour.
b) P( deli will sell 12 or more newspapers in a given hour)
P(x > 12)
[tex]P( x > 12) = P( z > \displaystyle\frac{12 - 10}{5}) = P(z > 0.4)[/tex]
[tex]= 1 - P(z \leq 0.4)[/tex]
Calculation the value from standard normal z table, we have,
[tex]P(x >12) = 1 - 0.655 = 0.345 = 34.5\%[/tex]
0.345 is the probability that the deli will sell 12 or more newspapers in a given hour.
