D. Reflect across line x =-7
Answer:
Step-by-step explanation:
Let the width be w centimeters.
Then the length = w + 7.
The area A is found from the length multiplied by the width.
330 = w(w + 7) = w^2 + 7w.
Now we can rearrange this equation to form a quadratic, as follows:
The factorization of the quadratic is:
(w + 22)(w - 15) = 0
Therefore we find that:
width = 15 centimeters
length = 22 centimeters
The sound intensity of rustling leaves, y = 20 decibels
<u>Step-by-step explanation:</u>
y = 10logx
The sound intensity of rustling leaves is 100 times the reference intensity.
x = ratio of intensity of sound to reference to intensity
x = 100:1 or x = 100
y = 10 log(100) = 10 * 2 = 20 decibels
y = 20 decibels
Answer:
Step-by-step explanation:
Given are 3 data sets with values as:
(i) 8 9 10 11 12 ... Mean =10
(ii) 7 9 10 11 13 ... Mean =10
(iii) 7 8 10 12 13 ... Mean =10
We see that data set shows mean deviations as
(i) -2 -1 0 1 2
(ii) -3 -1 0 1 3
(iii) -3 -2 0 2 3
Since variance is the square of std deviation, we find that std deviation is larger when variance is larger.
Variance is the sum of squares of (x-mean). Whenever x-mean increases variance increases and also std deviation.
Hence we find that without calculations also (i) has least std dev followed by (ii) and then (iii)
(i) (ii) (iii) is the order.
b) Between (i) and (ii) we find that 3 entries are the same and 2 entries differ thus increasing square by 9-4 twice. But between (ii) and (iii) we find that
increase in square value would be 4-1 twice. Obviously the latter is less.
