All categories

4 years ago

How would you characterize the relationships between the hours spent on homework and the test scores?

Mathematics

1 answer:

Elena-2011 [213]4 years ago

5 0

Answer:

There is a positive correlation because the more hours spent on homework the better the test score generally it.

Step-by-step explanation:

Since the graph has a positive slope and the data is close together, it looks to have positive correlation.

There is a positive correlation because the more hours spent on homework the better the test score generally it.

You might be interested in

Write an expression, using an exponent, that is equivalent to 9\times 9\times 9\times 9\times 9\times 9\times 99×9×9×9×9×9×9

jeka57 [31]

Nine to the eighth power

7 0

3 years ago

Read 2 more answers

Prove or disprove (from i=0 to n) sum([2i]^4) <= (4n)^4. If true use induction, else give the smallest value of n that it doe

ddd [48]

Answer:

The statement is true for every n between 0 and 77 and it is false for $n\geq 78$

Step-by-step explanation:

First, observe that, for n=0 and n=1 the statement is true:

For n=0: $\sum^{n}_{i=0} (2i)^4=0 \leq 0=(4n)^4$

For n=1: $\sum^{n}_{i=0} (2i)^4=16 \leq 256=(4n)^4$

From this point we will assume that $n\geq 2$

As we can see, $\sum^{n}_{i=0} (2i)^4=\sum^{n}_{i=0} 16i^4=16\sum^{n}_{i=0} i^4$ and $(4n)^4=256n^4$ . Then,

$\sum^{n}_{i=0} (2i)^4 \leq(4n)^4 \iff \sum^{n}_{i=0} i^4 \leq 16n^4$

Now, we will use the formula for the sum of the first 4th powers:

$\sum^{n}_{i=0} i^4=\frac{n^5}{5} +\frac{n^4}{2} +\frac{n^3}{3}-\frac{n}{30}=\frac{6n^5+15n^4+10n^3-n}{30}$

Therefore:

$\sum^{n}_{i=0} i^4 \leq 16n^4 \iff \frac{6n^5+15n^4+10n^3-n}{30} \leq 16n^4 \\\\ \iff 6n^5+10n^3-n \leq 465n^4 \iff 465n^4-6n^5-10n^3+n\geq 0$

and, because $n \geq 0$ ,

$465n^4-6n^5-10n^3+n\geq 0 \iff n(465n^3-6n^4-10n^2+1)\geq 0 \\\iff 465n^3-6n^4-10n^2+1\geq 0 \iff 465n^3-6n^4-10n^2\geq -1\\\iff n^2(465n-6n^2-10)\geq -1$

Observe that, because $n \geq 2$ and is an integer,

$n^2(465n-6n^2-10)\geq -1 \iff 465n-6n^2-10 \geq 0 \iff n(465-6n) \geq 10\\\iff 465-6n \geq 0 \iff n \leq \frac{465}{6}=\frac{155}{2}=77.5$

In concusion, the statement is true if and only if n is a non negative integer such that $n\leq 77$

So, 78 is the smallest value of n that does not satisfy the inequality.

Note: If you compute $(4n)^4- \sum^{n}_{i=0} (2i)^4$ for 77 and 78 you will obtain:

$(4n)^4- \sum^{n}_{i=0} (2i)^4=53810064$

$(4n)^4- \sum^{n}_{i=0} (2i)^4=-61754992$

7 0

4 years ago

How do you solve this pls help

Ne4ueva [31]

The first one is right because the mean is the average so it has to be in between. Usually. Hoped this helped!

3 0

3 years ago

Circle the greater fraction then right and saw the subtraction problem to find the difference of the fractions 9/10 11/12

Anon25 [30]

11/12 is the greater fraction.

2/60

4 0

4 years ago

The larger of two numbers is 7 times the smaller number. 3 times the larger number is 7 more than 4 times the smaller number. Fi

zhenek [66]

So the larger number is x, and the smaller number is y
7y=x
3x=7+4y

(So plug in the 7y=x information into the second equation)

3(7y)=7+4y
21y=7+4y
17y=7
y=7/17

5 0

3 years ago