Help please.<br> 1.) 12x+9x+15x<br><br> 2.) 7n+28-21m

The mass of a dust particle is 0.000000000753 kg. How would this number be written in scientific notation?

KengaRu [80]

$7.53 \times {10}^{ - 10}$

6 0

4 years ago

last summer at Camp okeefenokee the ratio of the number of a boy campers to the number of girl campers with 8:7. If there were a

Stels [109]

Number of boys=x
number of girls=y.

We can suggest this system of equations:
x/y=8/7 ⇒x=8y/7
x+y=195

this system of equations can be solve by substitution method.

(8y/7)+y=195
least common multiple=7
8y+7y=1365
15y=1365
y=1365/15
y=91

x=8y/7
x=8*91 / 7
x=728/7
x=104

Answer: there were 104 boy campers and 91 girl campers.

6 0

3 years ago

Someone help...anyone

Colt1911 [192]

Answer:

y=6x is your answer

Have a good day Ahead

5 0

3 years ago

Read 2 more answers

The correlation between the height and weight of children aged 6 to 9 is found to be about r = 0.8. Suppose we use the height x

Andrew [12]

Answer:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

The value of r is always between $-1 \leq r \leq 1$

And we have another measure related to the correlation coefficient called the R square and this value measures the % of variance explained between the two variables of interest, and for this case we have:

$r^2 = 0.8^2 = 0.64$

So then the best conclusion for this case would be:

c. the fraction of variation in weights explained by the least-squares regression line of weight on height is 0.64.

Step-by-step explanation:

For this case we know that the correlation between the height and weight of children aged 6 to 9 is found to be about r = 0.8. And we know that we use the height x of a child to predict the weight y of the child

We need to rememeber that the correlation is a measure of dispersion of the data and is given by this formula:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

The value of r is always between $-1 \leq r \leq 1$

And we have another measure related to the correlation coefficient called the R square and this value measures the % of variance explained between the two variables of interest, and for this case we have:

$r^2 = 0.8^2 = 0.64$

So then the best conclusion for this case would be:

c. the fraction of variation in weights explained by the least-squares regression line of weight on height is 0.64.

3 0

3 years ago

Which division fact corresponds to the problem of 8×9 equals 72

kondor19780726 [428]

Basically just do the problem backwards.
72÷9=8
72÷8=9

7 0

4 years ago

Help please. 1.) 12x+9x+15x 2.) 7n+28-21m