8 times the sum of 2 and 15

The diameter of a circle is 14ft. What is the circle's area?

galina1969 [7]

Answer:

153.95 feet²

Step-by-step explanation:

Area = pi × r²

radius= 7ft (half of diameter)

3.14 × 7 × 7= 153.95

7 0

2 years ago

What is the factor of 25a2+b2?

Neko [114]

Answer:

(5a+b)⋅(5a−b)

Step-by-step explanation:

Changes made to your input should not affect the solution:

(1): "b2" was replaced by "b^2". 1 more similar replacement(s).

STEP

1

:

Equation at the end of step 1

52a2 - b2

STEP

2

:

Trying to factor as a Difference of Squares

2.1 Factoring: 25a2-b2

Theory : A difference of two perfect squares, A2 - B2 can be factored into (A+B) • (A-B)

Proof : (A+B) • (A-B) =

A2 - AB + BA - B2 =

A2 - AB + AB - B2 =

A2 - B2

Note : AB = BA is the commutative property of multiplication.

Note : - AB + AB equals zero and is therefore eliminated from the expression.

Check : 25 is the square of 5

Check : a2 is the square of a1

Check : b2 is the square of b1

Factorization is : (5a + b) • (5a - b)

7 0

3 years ago

A data set consists of 2, 2, 3, 4, 5, 5, and 7. Then, 20 is added to the data set. The new value will have little effect on the

ale4655 [162]

Answer:

A data set consists of 2,2,3,4,5,5 and 7. Then, 20 is added to the data set. The new value will have the little effect on the median, but it will raise the mean significantly.

Step-by-step explanation:

Since, we all know that the measures of central tendency are:

Arithmetic Mean
Median
Mode
Geometric Mean
Harmonic Mean

Let us define Arithmetic Mean and Median.

Arithmetic mean is the sum of observations divided by the total number of observations. It is denoted by (x bar).

On the other hand, median of a distribution is that value of the variable which divides it into two equal parts.

For Arithmetic Mean:

According to the question, when data set consists 2,2,3,4,5,5 and 7, the arithmetic mean for the given data = 4

After adding 20 the given data set, the mean will be = 6

For median:

When data set consists of 2,2,3,4,5,5 and 7, the median value will be the middle value of the distribution i.e. = 4

After adding 20 to the given data set, the median will be = 4.5

Here we can say that 20 is an outlier for the given data set.

Since mean has the significant effect of the outlier because it is based on all values but the median has lesser effects of the outlier as it is based only on middle values. So whatever outlier is added to median, it will not show particular changes.

Thus , a data set consists of 2,2,3,4,5,5 and 7. Then, 20 is added to the data set. The new value will have little effect on median, but it will raise the mean significantly.

6 0

2 years ago

In a simple regression analysis for a given data set, if the null hypothesis β = 0 is rejected, then the null hypothesis ρ = 0 i

kati45 [8]

Answer:

Null hypothesis: $\rho =0$

Alternative hypothesis: $\rho \neq 0$

The statistic to check the hypothesis is given by:

$t=\frac{r \sqrt{n-2}}{\sqrt{1-r^2}}$

And is distributed with n-2 degrees of freedom

And the statistic to check the significance of a coeffcient in a regression is given by:

$t_1 = \frac{\hat{\beta_1} -0}{S.E (\hat{\beta_1})}$

For this case is importantto remember that t1 and p value for test of slope coefficient is the same test statistic and p value for the correlation test so then the answer would be:

Always

Step-by-step explanation:

In order to test the hypothesis if the correlation coefficient it's significant we have the following hypothesis:

Null hypothesis: $\rho =0$

Alternative hypothesis: $\rho \neq 0$

The statistic to check the hypothesis is given by:

$t=\frac{r \sqrt{n-2}}{\sqrt{1-r^2}}$

And is distributed with n-2 degrees of freedom

And the statistic to check the significance of a coeffcient in a regression is given by:

$t_1 = \frac{\hat{\beta_1} -0}{S.E (\hat{\beta_1})}$

For this case is importantto remember that t1 and p value for test of slope coefficient is the same test statistic and p value for the correlation test so then the answer would be:

Always

4 0

3 years ago

Please help me with my homework please answer this correctly

sleet_krkn [62]

6 then thousandths=60,000
1 more thousandth then 10,000=11,000
No hundreths=000
3 more tens then 10,000=40,000
And 4 fewer ones than 10,000=9,996
Add that all together and you get 121, 996

5 0

3 years ago