Answer:
<em>The observed t (2.533) is in the tail cut off by the critical t (2.462), therefore we reject H0. It is likely that the books are older than 20 years of age on average.</em>
Step-by-step explanation:
<em>Step 1: Hypotheses and α level
</em>
H0: μ ≤ 20
H1: μ > 20
<u><em>α = 0.01</em></u>
<em>Step 2: Critical region
</em>
α = .01
One-tailed
df = n – 1 = 30 – 1 = 29
<u><em>t - critical = 2.462
</em></u>
<em>Step 3: Calculate t which is observed
</em>
sM = √(s2 / n) = √(67.5 / 30) = 1.5
t = (M – μ) / sM
t = (23.8 – 20) / 1.5
<u><em>t = 2.533
</em></u>
<u><em /></u>
Answer: associative property
That's they are equal
7+(a+b)=(7+a)+b
Step-by-step explanation:
Answer:
16
Step-by-step explanation:
add
She had to make a 90 flat
hope this helps (;
Answer:
225
Step-by-step explanation:
A = 5. 3A = 3(5) cubed. So 3 times 5 is 15. 15 cubed is 225.