Answer:the number of BlackBerry that Arlene had initially was 276
Step-by-step explanation:
Let x represent the number of BlackBerry that Arlene had initially.
She gave 216 to her teachers. This means that she is left with x - 216
Then she dropped 12. This means that she would be left with x - 216 - 12 = x - 228
Later, she ate 18. This means that she would be left with x - 228 - 18 = x - 246
Finally, she gave half of what she had to her friend. This means that the amount that she gave to her friend is (x - 246)/2 and the amount that she has left would be
(x - 246)/2
Now, she has 15. This means that
(x - 246)/2 = 15
x - 246 = 2 × 15 = 30
x = 30 + 246 = 276
To solve this problem you must apply the proccedure shown below:
1. You have that the equation of the ellipse is the following:
(x²/400)+(y²/256)=1
2. You have that:
((x-0)²/400)+((y-0)²/256)=1
3. Then, the center is:
(0,0)
4. The vertices are:
a²=400
a=√400
a=20
(-20,0)
(20,0)
b²=256
b=√256
b=16
(0,-16)
(0,16)
5. The focci is:
a²–c²=b²
√(400-256)=c
c=12
(-12,0)
(12,0)
Answer:
x = 4
Step-by-step explanation:
expand out the brackets to get 7 - 2x = 2x - 8 - 1
we can then add 2x to both sides to get 7 = 4x - 8 - 1
add 9 to both sides to get 16 = 4x
divide both sides by 4 to get x = 4
hope that helps
HE WOULD PAY $5.52 FOR 12 STAMPS BECAUSE 8.28/18=0.46 THE YOU USE 0.46 X 12 = AND GET $5.52
The standard deviation of a point estimator is the <u>standard error.</u>
"The point estimate is used to estimate the exact value of any parameter. For example, an internet poll says that 45% of Americans are concerned for the environment."
"Point estimates is a good measure but the problem with this parameter is that the sample of the statistics may vary so that there is a chance of sampling error."
"As the researcher is unable to presume that closeness of the sample statistics parameter with respect to the parameter so researcher refers to calculate the standard error instead of point estimate."
To learn more about standard error here
brainly.com/question/13179711
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