Answer:
0.0089
Step-by-step explanation:
given,
mean of average american Car (μ) = 3750 pounds
standard deviation (σ) = 200 pound
n = 10
sample average = [tex]\bar{x} = \dfrac{39000}{10}[/tex]
= 3900 pounds
[tex]\mu_{\bar{x}} = 3750\ ponds[/tex]
[tex]\sigma_{\bar{x}} = \dfrac{\sigma}{\sqrt{n}}[/tex]
[tex]\sigma_{\bar{x}} = \dfrac{200}{\sqrt{10}}[/tex]
[tex]\sigma_{\bar{x}} = 63.25[/tex]
[tex]P(\bar{x}>3900) = 1 - P(\bar{x}<3900)[/tex]
= [tex]1 - P[\dfrac{\bar{x}-\mu_{\bar{x}}}{\sigma_{\bar{x}}}<\dfrac{3900-3750}{63.25}][/tex]
= 1 - P(Z<2.37)
using z- table
= 1 - 0.9911
= 0.0089