Answer:
Hence, the answer is [tex]x>71.1515[/tex]
Step-by-step explanation:
We have,
[tex]n=100,\mu=70,\sigma=7[/tex]
The top percentage of the students is [tex]5\%[/tex]
The lower percentage of the students is [tex]95\%[/tex]
The lowest [tex]95\%[/tex] is the left area from the normal distribution table, the area [tex]0.95[/tex] lies in the z-table
[tex]z=1.645[/tex] from the z- table
[tex]P(z<1.645)=0.95\\P(z>1.645)=0.05\\z>1.645[/tex]
[tex]\frac{x-\mu}{\frac{\sigma}{\sqrt{\mu}} } >1.645\\x>1.645\times \frac{\sigma}{\sqrt{n}} +\mu[/tex]
[tex]>1.645\times \frac{7}{\sqrt{100}} +70[/tex]
[tex]\Rightarrow x>71.1515[/tex]