Answer:
Step-by-step explanation:
The number of samples is large(greater than or equal to 30). According to the central limit theorem, as the sample size increases, the distribution tends towards normal. The formula is
z = (x - µ)/(σ/√n)
Where
x = sample mean
µ = population mean
σ = population standard deviation
n = number of samples
From the information given,
µ = 22199
σ = 5300
n = 30
the probability that a senior owes a mean of more than $20,200 is expressed as
P(x > 20200)
Where x is a random variable representing the average credit card debt for college seniors.
For n = 30,
z = (20200 - 22199)/(5300/√30) =
- 2.07
Looking at the normal distribution table, the probability corresponding to the z score is 0.0197
P(x > 20200) = 0.0197
Answer:
3x³ + 23x² + 63x + 55
Step-by-step explanation:
Given
(3x + 5)(x² + 6x + 11)
Each term in the second factor is multiplied by each term in the first factor, that is
3x(x² + 6x + 11) + 5(x² + 6x + 11) ← distribute both parenthesis
= 3x³ + 18x² + 33x + 5x² + 30x + 55 ← collect like terms
= 3x³ + 23x² + 63x + 55
Answer: choice C) -15x^4y
-----------------------------------------
Explanation:
The coefficients are -3 and 5. They are the numbers to the left of the variable terms
Multiply the coefficients to get -3*5 = -15. So -15 is the coefficient in the answer
Multiply the x terms to get x^3 times x = x^(3+1) = x^4. Notice the exponents are being added
Do the same for the y terms as well: y^2 times y^(-1) = y^(2+(-1)) = y^(2-1) = y^1 = y
So we have a final coefficient of -15, the x terms simplify to x^4 and the y terms simplify to just y
Put this all together and we end up with -15x^4y which is what choice C is showing