Answer:
2401
Step-by-step explanation:
Given that we want to estimate average income in a population.
The standard deviation of income in the population is $1,000
We want confidence interval around our estimate to be +/- $40
i.e Margin of error = 40
We know that margin of error = Std error * Z critical for 95%
i.e. 
Std error = 
Together we get

Answer:
7.5 years
Step-by-step explanation:
P = $5000,
R = 4.25%,
A = $6593.75,
N =?
SI = A - P = 6593.75 - 5000 =$1593. 75

Answer:
The test contains 10 three-point questions and 14 five-point questions.
Step-by-step explanation:
The value of x is the number of 3-point questions, and the value of y is the number of 5-point questions, as the problem statement tells you. So, the solution (x, y) = (10, 14) indicates ...
"The test contains 10 three-point questions and 14 five-point questions."
_____
You can try the offered answers to see which might apply. The last choice has too many questions. The first and third choices don't add up to 100 points.
Answer:the uncle is 54 years old.
The woman is 18 years old
Step-by-step explanation:
Let x represent the age of the uncle.
Let y represent the age of the woman that he married.
In the film, an actor played an elderly uncle character is criticized for marrying a woman when he is 3 times her age. This means that
x = 3y
He wittily replies, "Ah, but in 18 years time I shall only be twice her age. It means that
x + 18 = 2(y + 18)
x + 18 = 2y + 36 - - - - - - - - - - 1
Substituting x = 3y into equation 1, it becomes
3y + 18 = 2y + 36
3y - 2y = 36 - 18
y = 18
x = 3y = 3 × 18
x = 54
Well first you got to add up of the sides