Question

PLZ HELP ME I NEED THIS ASAP

Answer 1

Mean = 110

Sample size = 45

Standard deviation = 6

Z score for 90% is 1.645 ( from Z-table).

Lower Limit = Mean - Z(SD/√Sample size))

Lower limit = 110 - 1.645(6/√45)

Lower limit = 108.5

Upper Limit = Mean + Z(SD/√Sample size))

Lower limit = 110 +1.645(6/√45)

Lower limit = 111.5

The interval is (108.5, 111.5)