Question 770754
1. P(70≤X≤80)≤
=P({{{(70-70)/10}}}≤Z≤{{{(80-70)/10}}}))
=P(0≤Z≤1)
=0.5-0.1587
=0.3413
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2. P(X≤62)
=P(Z≤{{{(62-70)/10}}})
=P(Z≤-0.8)
=0.2119
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3. P(56≤X≤72)
=P({{{(56-70)/10}}}≤Z≤{{{(72-70)/10}}}))
=P(-1.4≤Z≤0.2)
=1-0.0808-0.4207
=0.4985