A irrational number is a number that can't be expressed as a ratio of two whole numbers. That's it.
For examples (in increasing order of difficulty)
1 is a rational number because it is 1/1
0.75 is a rational number because it is equal to 3/4
2.333... (infinite number of digits, all equal to three) is rational because it is equal to 7/3.
sqrt(2) is not a rational number. This is not completely trivial to show but there are some relatively simple proofs of this fact. It's been known since the greek.
pi is irrational. This is much more complicated and is a result from 19th century.
As you see, there is absolutely no mention of the digits in the definition or in the proofs I presented.
Now the result that you probably hear about and wanted to remember (slightly incorrectly) is that a number is rational if and only if its decimal expansion is eventually periodic. What does it mean ?
Take, 5/700 and write it in decimal expansion. It is 0.0057142857142857.. As you can see the pattern "571428" is repeating in the the digits. That's what it means to have an eventually periodic decimal expansion. The length of the pattern can be anything, but as long as there is a repeating pattern, the number is rational and vice versa.
As a consequence, sqrt(2) does not have a periodic decimal expansion. So it has an infinite number of digits but moreover, the digits do not form any easy repeating pattern.
Answer:
(-0.1059 ; - 0.0337)
Step-by-step explanation:
The data table is attached in the picture below:
These is a matched pair design ; which requires taking the difference of the two values for each sample :
The mean and standard deviation of the difference will be used to construct the confidence interval :
The mean of difference, dbar = Σx/n = - 0.0698
The standard deviation of difference, Sd ;
Sd = [√Σ(d - dbar)²/(n-1)] = 0.1054
n = sample size = 25
The confidence interval :
dbar ± [TCritical * Sd/√n]
Tcritical at 90% ; df = n -1 = 25 -1
Tcritical(90% , 24) = 1.1711
C.I = - 0.0698 ± (1.711 * 0.1054/√25)
C.I = - 0.0698 ± 0.0361
C.I = (-0.1059 ; - 0.0337)
Answer: you need 5000 more
Step-by-step explanation: 70000 + 5000= 75000
An equation to represent this would be 12x+2=T.
x=10 people per large table.
If T=122 then we just have to isolate x on one side of the equation. The first step is to replace T with 120 and then subtract 2 on both sides (to cancel the +2) to get 12x=120. Cancel the 12 by dividing both sides by 12 to get x=10. The number of people seated at each large table would be 10. Hopefully I explained this correctly and helped you understand.
