Your medical research team is investigating the standarddeviationofthe cost of a30-day supply of a certain heart medication. A pharmaceutical company thinks that the standarddeviationofthe cost is lessthan$18. You want to support this claim. How would you write the null and alternativehypotheses?

H0:

sigma greater than or equals 18

18

sigma greater than 18

>18

sigma not equals 18

18

sigma less than or equals 18

18

sigma less than 18

<18

sigma equals 18

=18

Ha:

sigma greater than 18

>18

sigma less than 18

<18

sigma equals 18

=18

sigma not equals 18

18

sigma less than or equals 18

18

sigma greater than or equals 18