Mwangazalimiteddealsintheproductionofelectronicbulbs.Arandomsampleof10electronic

bulbsproducedbythecompanyyieldedthefollowingresultsonthelifetimeofthebulbs.

Lifetime(hours)

400

,

5

000

,

4

100

,

4

700

,

3

000

,

4

500

,

5

900

,

3

700

,

3

800

,

4

400

,

4

Required:

Testata%

5

percentlevelofsignificance,whetherthereisasignificantdifferencebetweenthe

samplemeanandthepopulationmean.

[6Marks] The hypothetical population mean of the lifetime of the electronic bulb is given as 4000 hours.