Number 5a. is 26.78 and 5b. is 8.5
Answer:
Constructive Proof
Step-by-step explanation:
Let x be a positive integer
x must be equal to sum of all positive integers exceeding it
i.e.
x = x + (x - 1) + ( x - 2) + ......... + 2 + 1
Equivalently,
x = ∑i (where i = 1 to x)
The property finite sum;
∑i (i = 1 to x) = x(x + 1)/2
So,
x = x(x + 1)/2 ------- Multiply both sides by 2
2 * x = 2 * x(x + 1)/2
2x = x(x + 1)
2x = x² + x ------- subtract 2x from both sides
2x - 2x = x² + x - 2x
0 = x² + x - 2x ----- Rearrange
x² + x - 2x = 0
x² - x = 0 ------ Factorise
x(x - 1) = 0
So,
x = 0 or x - 1 = 0
x = 0 or x = 1 + 0
x = 0 or x = 1
But x ≠ 0
So, x = 1
The statement is only true for x = 1
This makes sense because 1 is the only positive integer not exceeding 1
1 = 1
It is a Constructive Proof
A proof is constructive when we find an element for which the statement is true.
Answer:
x =30
Step-by-step explanation:
in order to evaluate the solution 4/5=20/(x-5)?
solution
the first step to take is to cross multiply
4/5=20/(x-5)
we have,
5 x 20 = 4 ( x -5)
100 = 4x - 20
combine the like terms
100+20 = 4x
120 = 4x
divide both sides by the coefficient of x
120/4 = 4x/4
30 = x
x =30
therefore the value of x in the expression 4/5=20/(x-5)? is 30
Answer:
4
Step-by-step explanation:
that was easy
Answer:
99% Confidence interval: (0.185,0.375)
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 150
Number of cars that have faulty catalytic converters, x = 42
99% Confidence interval:
Putting the values, we get:
The 99% confidence interval for the true proportion of new cars with faulty catalytic converters is (0.185,0.375)
