Charmaine= x
William=x+3
3 times Charmaine = 3x
2times William = 2x+6
5x+6=76
5x=76-6
5x=70
X=14
Charmaine is 14
William is 3 years older so is 17
Check:
17x2= 34
14x3=42
34+42=76
So Charmaine is 14
William is 17
For this problem, the confidence interval is the one we are looking
for. Since the confidence level is not given, we assume that it is 95%.
The formula for the confidence interval is: mean ± t (α/2)(n-1) * s √1 + 1/n
Where:
<span>
</span>
α= 5%
α/2
= 2.5%
t
0.025, 19 = 2.093 (check t table)
n
= 20
df
= n – 1 = 20 – 1 = 19
So plugging in our values:
8.41 ± 2.093 * 0.77 √ 1 + 1/20
= 8.41 ± 2.093 * 0.77 (1.0247)
= 8.41 ± 2.093 * 0.789019
= 8.41 ± 1.65141676
<span>= 6.7586 < x < 10.0614</span>
Answer:
D
Step-by-step explanation:
4 + 12 + 18 + 68= 102/2 51
40 + 28 + 52 + 76= 196/2 98
51:98
The above questions answer is 8 and 14
