Given:
n = 20, sample size
xbar = 17.5, sample mean
s = 3.8, sample standard deiation
99% confidence interval
The degrees of freedom is
df = n-1 = 19
We do not know the population standard deviation, so we should determine t* that corresponds to df = 19.
From a one-tailed distribution, 99% CI means using a p-value of 0.005.
Obtain
t* = 2.8609.
The 99% confidence interval is
xbar +/- t*(s/√n)
t*(s/√n) = 2.8609*(3.8/√20) = 2.4309
The 99% confidence interval is
(17.5 - 2.4309, 17.5 + 2.4309) = (15.069, 19.931)
Answer: The 99% confidence interval is (15.07, 19.93)
The equation of the piecewise function is 
<h3>The piecewise function</h3>
On the graph, we have:
- y = 3 for all x values not more than -1
- y = -1 for all values greater than 2
Hence, the piecewise function is:
<h3>The domain of the function</h3>
This is the set of input values
In (a), we have:
x ≤ -1 and x > 2
Hence, the domain is (∞, 3] u (2, ∞)
<h3>The range of the function</h3>
This is the set of output values
In (a), we have:
f(x) = 3 and f(x) -1
Hence, the range is [3] u (-1)
Read more about piecewise function at:
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There are no real roots for a negative number, so -81 has no real roots, if the number is 81 however, then the tow roots are 9
D
Due to the question being the question
Answer:
2√15
Step-by-step explanation:
