Gauss' method for addition relies on the fact that you can 'pair' certain numbers together. Look at the example:
1+2+3+4+5+6+7+8+9+10
We could manually add all these together from left to right but a clever way to think about this is if we add together the ends of the sum (10+1) we get 11. If we then move one in from the ends and add these (2+9) we also get 11. This means that 1+2+...+9+10 is the same as 11+11+...+11+11.
Because each 2 numbers adds to 11 we know the total number of 11's we have to add together is the length of the sum divided by 2. In our case 5 (10 ÷ 2). We need to add 5 lots of 11 to get our answer. This is the same as 11 × 5 which is easily seen to be 55.
(If you add the 10 numbers together on a calculator you'll see 1+2+3+4+5+6+7+8+9+10 = 55) so this method really makes it a lot quicker.
Looking at your sequence, if we pair the ends together we get 401 (400+1) and we multiply this by the length of the sequence divided by 2. In your case, 200 (400 ÷ 2).
So the sum of all the numbers from 1 to 400 must be 401 × 200 = 80,200.
Remember the steps:
1. Pair the ends together and add them
2. Times this number by the length of the sequence halved
Hope this helps.
Answer:
Part 1
Type II error
Part 2
No ; is not ; true
Step-by-step explanation:
Data provided in the question
Mean = 100
The Random sample is taken = 43 students
Based on the given information, the conclusion is as follows
Part 1
Since it is mentioned that the classes are successful which is same treated as a null rejection and at the same time it also accepts the alternate hypothesis
Based on this, it is a failure to deny or reject the false null that represents type II error
Part 2
And if the classes are not successful so we can make successful by making type I error and at the same time type II error is not possible
Therefore no type II error is not possible and when the null hypothesis is true the classes are not successful
It would be: 3(x + 21) ≤ -26
3x + 21 ≤ -26
3x ≤ -47
x < -47/3
In short, Your Answer would be -47/3 or 15.67
Hope this helps!
