If x is a real number such that x3 + 4x = 0 then x is 0”.Let q: x is a real number such that x3 + 4x = 0 r: x is 0.i To show that statement p is true we assume that q is true and then show that r is true.Therefore let statement q be true.∴ x2 + 4x = 0 x x2 + 4 = 0⇒ x = 0 or x2+ 4 = 0However since x is real it is 0.Thus statement r is true.Therefore the given statement is true.ii To show statement p to be true by contradiction we assume that p is not true.Let x be a real number such that x3 + 4x = 0 and let x is not 0.Therefore x3 + 4x = 0 x x2+ 4 = 0 x = 0 or x2 + 4 = 0 x = 0 orx2 = – 4However x is real. Therefore x = 0 which is a contradiction since we have assumed that x is not 0.Thus the given statement p is true.iii To prove statement p to be true by contrapositive method we assume that r is false and prove that q must be false.Here r is false implies that it is required to consider the negation of statement r.This obtains the following statement.∼r: x is not 0.It can be seen that x2 + 4 will always be positive.x ≠ 0 implies that the product of any positive real number with x is not zero.Let us consider the product of x with x2 + 4.∴ x x2 + 4 ≠ 0⇒ x3 + 4x ≠ 0This shows that statement q is not true.Thus it has been proved that∼r ⇒∼qTherefore the given statement p is true.
Answer:
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 40 dollars
Standard Deviation, σ = 7 dollars
Sample size,n = 51
We are given that the distribution of cost of shrimp is a bell shaped distribution that is a normal distribution.
Formula:
Standard error due to sampling =
P(sample mean would differ by true mean by more than 0.6)
0.5404 is the required probability.
A) The total number is the sum of all the frequencies
2+5+8+12+11+6=44
Answer: 44
B) The width is (upper limit - lower limit) / 2
(35-21) / 2 = 7
(50-36) / 2 = 7
(65-51) / 2 = 7
(80-66) / 2 = 7
(95-81) / 2 = 7
(110-96) / 2 = 7
Answer: the width is 7
C) The midpoint is the lower limit + the width
36+7=43
Answer: the midpoint is 43
D)The modal is the class with more frequency
In this case 66-80 with 12
Answer: class 66-80
E) We use the width formula
lower limit = 111
width = 7
upper = (width * 2) - lower
upper = (7 * 2) + 111
upper = 125
Answer: class 111-125
Answer: 
Step-by-step explanation:
Given
Apply cross-multiplication
The value of k is 
<span>A = hours for plan A
B = hours for plan B</span>
<span>Monday: 6A + 5B = 7
Tuesday: 2A + 3B = 3</span>
use elimination by multiplying the 2nd equation by 3.
Doing that we get 3(2A + 3B = 3) = 6A + 9B
= 9
<span>So the two equations are now:
6A + 9B = 9</span>
6A + 5B = 7
Subtract and we have 4B = 2
B = 2/4 = 1/2 of an hour
Now put 1/2 back into either equation to solve for A
<span>6A + 5(1/2) = 7
6A + 5/2 = 7
6A = 14/2 -5/2
6A = 9/2
divide by 6 to get A = 9/12 = ¾ hours</span>
<span>Plan A = 3/4 hour</span>
<span> Plan B = 1/2 hour</span>
