Step-by-step explanation:
the mean value is the sum of all data points divided by the number of data points.
first we have 7 tests and their mean value :
(t1 + t2 + t3 + t4 + t5 + t6 + t7) / 7 = 54
that means
(t1 + t2 + t3 + t4 + t5 + t6 + t7) = 54 × 7 = 378
in order for the mean value to be at least 60% after 8 tests, we need to add a t8, so that
(t1 + t2 + t3 + t4 + t5 + t6 + t7 + t8) = 60 × 8 = 480
because only then we have
(t1 + t2 + t3 + t4 + t5 + t6 + t7 + t8) / 8 = 60
and the student passes.
so,
(t1 + t2 + t3 + t4 + t5 + t6 + t7) + t8 = 480
378 + t8 = 480
t8 = 480 - 378 = 102%
the student would have to achieve 102% on the 8th test.
which would be normally impossible, but maybe the tests involve some bonus points.
Answer: y = -4x - 4
Step-by-step explanation:
Point slope form: y - y1 = m(x - x1)
Plug in y1 and x1, and m. M is the slope, x1 and y1 are the values for a coordinate. You don't need to plug anything in for y or x, just y1 and x1.
First, find the slope. To find the slope, use this "formula" : 
Find two coordinate points. Let's use (-2,4) and (0,-4). Based on this, we know that y1 is 4, y2 is -4, x1 is -2, and x2 is 0. Plug these into the formula:
Then, pick any point to plug into the equation. Let's use (0,-4)
Finally, plug everything into the equation:
y - - 4 = -4(x - 0)
y + 4 = -4x
y = -4x - 4
Answer:
Explained below :)
(I tried my best, sorry if it doesn't make sense.)
Step-by-step explanation:
Example: 1/4 - 1/8= ?
1: Find the common denominator (bottom number)
2: If the common denominator is 8 then you multiply 1/4 by 2/2 to get the denominator of 8. If you needed then you can multiply the other fraction to get the same denominator.
3: Once you get multiply that then you get 2/8 -1/8.
4: Subtract the numerator (top number) 1
5: Keep the numerator (8)
6: Your answer would be 1/8
Answer:
810
Step-by-step explanation:
In this case the sample space would be the number of combinations that can be made with the numbers from 1 to 30 with the letters of the alphabet, from "a" to "z", for example:
A1, A22, C4, F9, etc
Now we know how many numbers are 30, now the alphabet has 27 letters, therefore, the number of combinations are:
27 * 30 = 810
Which means that the total number of results is 810.
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