It’s c. 5. i’m sorry if it’s wrong

Actually Welcome to the Concept of the Differential Calculus.
Since, we know this is a definite calculus,
thus we get here as, by using the Chain Rule.
1.99 divided by 12 would give u about 0.66$
Answer:
There is sufficient evidence to support the claim that the standard deviation is less than 14.7.
Step-by-step explanation:
From the question we are told that that the null hypothesis is

Now given from the question that this null hypothesis was rejected, it mean, in non technical term that there is sufficient evidence to support the claim that the standard deviation is less than 14.7.