Answer:
(115.2642, 222.7358).
Step-by-step explanation:
Given data:
type A: n_1=60, xbar_1=1827, s_1=168
type B: n_2=180, xbar_2=1658, s_2=225
n_1 = sample size 1, n_2= sample size 2
xbar_1, xbar_2 are mean life of sample 1 and 2 respectively. Similarly, s_1 and s_2 are standard deviation of 1,2.
a=0.05, |Z(0.025)|=1.96 (from the standard normal table)
So 95% CI is
(xbar_1 -xbar_2) ± Z×√[s1^2/n1 + s2^2/n2]
=(1827-1658) ± 1.96×sqrt(168^2/60 + 225^2/180)
= (115.2642, 222.7358).
Answer:
ummm i dont know but try 16 35/21
Step-by-step explanation:
Answer:
1194 students last year
Step-by-step explanation:
The problem statement tells us ...
98% × (students last year) = 1170
Dividing by 98%, we get ...
1170/0.98 = (students last year) = 1193.88 ≈ 1194
___
<em>Check</em>
1170/1194 = 0.979899... ≈ 0.98 = 98%
Answer:
The perimeter is 54 square units
Step-by-step explanation:
You find the sum of 12+12 and that's 24, and 15+15, and that is 30, and 30+24 is 54.
Hope this helped!
Answer:
x = 38, y = 4
Step-by-step explanation:
Since AB = BC then the triangle is isosceles and the base angles are congruent, that is
∠ DAB = ∠ DCB = 52°
Subtract the sum of the base angle from 180° for ∠ ABC
∠ ABC = 180° - (52 + 52)° = 180° - 104° = 76°
Note that ∠ ABD = ∠ CBD, thus
x = 76 ÷ 2 = 38
BD bisects the side AC, thus DC = AD = 4
Thus y = 4
