95 % CI="\\bar x\u00b1Z_\\frac{\\alpha}{2}\\frac{\\sigma}{\\sqrt n}"
a) "\\bar x=100"
="100\u00b11.96* \\frac {20}{\\sqrt{25}}"
=(92.16, 107.84)
b)"\\bar x=200"
"=200\u00b11.96* \\frac {20}{\\sqrt{25}}"
=(192.16, 207.84)
c) "\\bar x=500"
="500\u00b11.96* \\frac {20}{\\sqrt{25}}"
=(492.16, 507.84)
d) As the sample mean increases the confidence interval width remains constant. This is because the standard error is constant for all sample means.
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