Let's make a table of differences
0 3 8 15 24
3 5 7 9
2 2 2
Constant second difference means a quadratic polynomial,
f(n)=an² + bn +c
f(1)=0, f(2)=3, f(3)=8
0 = a+b+c
3 = 4a + 2b + c
8 = 9a + 3b + c
Subtracting pairs
3 = 3a+b
5 = 5a + b
Subtracting,
2 = 2a
a = 1
b = 5 - 5a = 0
c = -a-b = -1
f(n)=n² -1
Duh, shoulda noticed that at the beginning.
f(17)=17²-1 = 288
a₁ =5
aₙ = aₙ₋₁ - 7
aₙ = a₁ + d(n-1)
aₙ = 5 - 7(n-1)
a₇ = 5 - 7(6) = -37
Answer: -37
Given:
Percent Amount $
Fund A 3% $4000
Fund B 1% x
Total Funds 8% $4000 + x
Find:
Fund B Investment
Solution:
$4000 * .03 + .10 * x = .08% ($4000 + x)
We already know 3 rates and one amount invested
$4000 * .03 + .10 * x = .08% ($4000 + x)
Multiply them out:
120 + (0.10 * x) = 320 + 0.08x
Now, we combine like terms.
.10x – 0.08x = 320 – 120
.02x = 200
Isolate x
x = 200 / 0.02
Divide
x = $10,000
Checking:
($4000 * .03) + (.10 * 10,000) = .08% ($4000 + 10,000)
120 + 1000 = 320 + 800
1120 = 1120
Therefore, fund B has an investment of $10,000.
Answer:
a) P(x>8) = 0.3937
b) P(x = 2) =0.04661
Step-by-step explanation:
a) From to find the probabilty that in this specific time period, more than 8 cars arrive at the intesection, we use the probability function thus
P(x>8) = 1 - P(x≤8), Cause you can use the complement for calculate this probability , then:
P(x≤8) = 
, until x= 8, then you obtain:
P(x≤8)=0.6063 and
P(x>8) = 1 - P(x≤8)= 1-0.6063 = 0.3937
b) P(x=2)= 
P(x = 2) =0.04661
Answer: The cost for 20 people equals $180.
Step-by-step explanation:
Given: It costs $100 to rent the bowling alley, plus $4 per person.
The cost for any number (n) of people can be found using the expression
We can find the cost for 20 people by substituting n=20 in the above expression, we get
Hence, The cost for 20 people equals $180.
