Question

Express the confidence interval (84.6,268.8) in the form of ¯x±ME.

Express the confidence interval 587.7<μ<814.5 in the form of ¯x±ME.

Answer 1

Solution :

  = (Lower confidence interval + Upper confidence interval ) / 2

Sample mean = = (84.6+268.8) / 2=176.7

Margin of error = E = Upper confidence interval -   = 268.8-176.7=92.1

¯x±ME.

176.7±92.1

b.

Solution :

  = (Lower confidence interval + Upper confidence interval ) / 2

Sample mean = = (587.7+814.58) / 2=701.14

Margin of error = E = Upper confidence interval -   = 814.58-701.14=113.44

x±ME

701.14±113.44