Answer:
Hence the correct option is option b) Yes, the upper level of one standard deviation is 72.
A score of 74 is not within one standard deviation of the mean.
Step-by-step explanation:
Here the given details are,
Mean = 68
SD = 4
Distribution is normal.
Z-score for x = 74 is given as below:
So, the score of 74 is 1.5 standard deviations from the mean.
Therefore the score is not lies between 64 and 72.
Yes, the upper level of one standard deviation is 72.
Answer:
Both answers will give an area of 2400 ft2
but with x=60 we have lawn dimensions -60 ft by -40 ft so this is out
x = 10 ft width for the sidewalk
Check: New lawn dimensions
(80-2x)(60-2x) = 60(40) = 2400 ft^2
Step-by-step explanation:
Draw a diagram:
We have a rectangle inside a rectangle.
The larger outside rectangle is the original lawn: 80ft by 60 ft with area 4800 ft2
The smaller inside rectangle is (80-2x)by(60-2x) where x is width of the new sidewalk.
Area of new lawn is 2400 ft^2
(80-2x)(60-2x) = 2400
4800 - 160x - 120x + 4x2 = 2400
4x2 - 280x + 2400 = 0
Factor out a 4
x2 - 70x + 600 = 0
(x-60)(x-10) = 0
x = 60 ft or x = 10 ft
Answer: X= -3/4, -1/2
Step-by-step explanation:
Answer:
35x^2-96X-108
Step-by-step explanation:hi
