Determine the value of z* such that
a.z* and 2z* separate the middle 95% of all z values from the most extreme 5%
b.z* and 2z* separate the middle 90% of all z values from the most extreme 10%
c.z* and 2z* separate the middle 98% of all z values from the most extreme 2%
d.z* and 2z* separate the middle 92% of all z values from the most extreme 8%