Answer:
Age of Mel is 25 years.
Step-by-step explanation:
It is given that,the sum of Ali and Mel's age is 39. If Mel is 3 years younger than twice Ali's age.
Let 'x' be the Ali's age and 'y' be the Mel's age
<u>To find the value of x and y</u>
sum of Ali and Mel's age is 39
⇒ x + y = 39 ------(1)
Mel is 3 years younger than twice Ali's age
⇒ y = 2x - 3 -------(2)
⇒ 2x - y = 3 -----(3)
(1) + (3) ⇒
x + y = 39
2x - y = 3
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3x = 42
x = 42/3 = 14
y = 2x - 3 = 14*2 - 3 = 25
Therefore the age of Ali = 14
Age of Mel = 25
So the mean is 72.97
We need to subtract the mean from each value and square it.
(65-72.97)^2= 63.5209
(68-72.97)^2=24.7009
(69-72.97)^2=15.7609
(70-72.97)^2=8.8209
(71-72.97)^2= 3.8809
(72-72.97)^2=0.9409
(90-72.97)^2=290.0209
(95-72.97)^2=485.3209
Now we add up the new values ( also consider their frequency) and find their mean.
Add the values
63.5209+(2 •24.7009=49.4018)+(5•15.7609=78.8045)+(8•8.8209=70.5672)+(7•3.8809=27.1663)+(3•0.9409=2.8227)+(2•290.0209=580.0418)+(2•485.3209=970.6418)= 1,842.967
Divide by total numburs to find the mean
1,842.967/ 30=61.43223333
The standar deviation is the square root of the mean so is
Square root of 61.43223333=7.837871735
Round to the nearest tenth
Standard Deviation is 7.8
Answer:
33.3
Step-by-step explanation:
tan A = opp/adj
tan 39° = 27/x
x tan 39° = 27
x = 27/(tan 39°)
x = 33.3
Step-by-step explanation:
the electromagnet lasts only as long as there is supply of electric current
Interval notation uses parenthesis ( or ) for points that are not included in the function (open circle) and brackets [ or ] for points that are included in the function (filled in circle).
Remember that the domain for a function is the range of x-values in a function.
Interval notation includes the numbers at the each end of a continuous function. For function F, the leftmost x-value is 0. The rightmost x-value is 8. Both points at x = 0 and x = 8 are included in the function (filled in circles), so you would use the brackets. The entire function is continuous between those two points.
That means the interval notation for the domain of F is:
[0, 8]
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Answer: [0, 8]
