Answer:
609
Step-by-step explanation:
Standard deviation = 
= $30
Margin of error = E = $2
Confidence level = 90%
Since the distribution is said to be normal, we will use z scores to solve this problem.
The z score for 90% confidence level = z = 1.645
Sample size= n = ?
The formula to calculate the margin of error is:
Using the values in above equation, we get:
This means, the minimum number of observations required is 609
The solution to the original equation is 1, 1/6
<h3>Solving equation</h3>
Equations are expressions separated by mathematical operations.
Given the equation below
x/x − 1 = 6x + 1/x − 1
From the given expression, the least common denominator is x -1
Multiply both sides by x-1 to have;
x = 6x(x-1) +1
Expand
x = 6x^2-6x + 1
Equate to zero
6x^2-6x-x + 1 = 0
6x^2-7x +1= 0
The resulting quadratic equation in general form is 6x^2-7x +1 = 0
Factorize
6x^2 -6x-x + 1 = 0
Group the result
6x(x-1)-1(x-1) = 0
(6x-1)(x-1) = 0
6x - 1 = 0 and x -1 = 0
x = 1 and 1/6
Hence the solution to the original equation is 1, 1/6
Learn more on equation here: brainly.com/question/13763238
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Answer:
£1638.40
Step-by-step explanation:
Step one:
Given data
A car costs £5000 when new
Each year the value decreases by 20%.
Step two:
let us compute the worth in the next 5 years
year 1
worth= 5000- 0.2*5000
worth= 5000-1000
worth= £4000
year 2
worth= 4000- 0.2*4000
worth= 4000-800
worth= £3200
year 3
worth= 3200- 0.2*3200
worth= 3200-640
worth= £2560
year 4
worth= 2560- 0.2*2560
worth= 2560-512
worth= £2048
year 5
worth= 2048- 0.2*2048
worth= 2048-409.6
worth= £1638.40
The person is wrong because after 5 years the car is worth £1638.40
For the first one it would be 10/3 ( 10 over 3 ) and for the second one, it would be 7/13 ( 7 over 13 ) PLUS 4i/13 ( 4i over 13)
I believe 63 would be correct
