Answer:
$870 in his bank account
Step-by-step explanation:
420 / 3 = 140
140 * 6 = 840
840 + 30 = 870
Answer:
adult cost £7, child cost £2
Step-by-step explanation:
let a represent an adult and c a child , then
2a + 3c = 20 → (1)
a + 4c = 15 → (2)
Multiplying (2) by - 2 and adding to (1) will eliminate a
- 2a - 8c = - 30 → (3)
Add (1) and (3) term by term to eliminate a, that is
- 5c = - 10 ( divide both sides by - 5 )
c = 2
Substitute c = 2 into either of the 2 equations and evaluate for a
Substituting into (2)
a + 4(2) = 15
a + 8 = 15 ( subtract 8 from both sides )
a = 7
The cost of an adult ticket is £7 and a child ticket is £2
The distribution of X is X ~ N (20 , 6) and the probability that this American will receive no more than 24 Christmas cards this year is 0.7486.
<h3>Probability</h3>
a. Distribution
X ~ N (20 , 6)
b. P(x ≤24)
= P[(x - μ ) / σ (24 - 20) / 6]
= P(z ≤0.67)
= 0.74857
=0.7486
Hence:
Probability = 0.7486
c. P(21 < x < 26)
= P[(21 - 26)/ 6) < (x - μ ) / σ < (24 - 20) / 6) ]
= P(-0.83 < z < 0.67)
= P(z < 0.67) - P(z < -0.)
= 0.74857- 0.2033
= 0.54527
Hence:
Probability =0.54527
d. Using standard normal table ,
P(Z < z) = 66%
P(Z < 0.50) = 0.66
z = 0.50
Using z-score formula,
x = z× σ + μ
x = 0.50 × 6 + 20 = 23
23 Christmas cards
Therefore the distribution of X is X ~ N (20 , 6) and the probability that this American will receive no more than 24 Christmas cards this year is 0.7486.
Learn more about probability here:brainly.com/question/24756209
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Answer:
The cost of her old laptop would be $52.
Step-by-step explanation:
