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:
d 1
Step-by-step explanation:
i might not be right
Anwser
C
I think
Wait not it’s can’t be c
D. Yeah d jdjddjslkfkd
Answer:
Right triangle
Step-by-step explanation:
7^2 + 6^2 = c^2
49 + 36 = c^2
85 = c^2
c = 9.22
(c)*(d)=8*30+8*4=8*34,=>
c=8
d=34
a+b>a-b, =>a+b=d, a-b=c; =>
{a+b=34
{a-b=8, =>a=b+8 ;
(b+8)+b=34
2b=34-8
b=13
a=13+8=21
Answer: a=21; b=13; c=8; d=34.