Answer:
21.75 cm/s
Step-by-step explanation:
1 cm above central position means D = 1, so we plug in 1 into D(t) and find the time and which this occurs.

This is the time at which this occurs.
To find instantaneous rate of change, we differentiate D(t) and plug in this t we found. Remembering that d/dt (Sin t) = Cos t

Now putting t:

Thus, the instantaneous rate would be around 21.75 cm/s
The original number to the nearest tenth is 23.8
Answer:
The standard deviation of the sample mean is 4 minutes
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean
and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this problem, we have that:
The standard deviation of the population is 32.
Sample of 64.
So

The standard deviation of the sample mean is 4 minutes
X^2 - 7x -12? good luck idk