PLs answer my question i need help pls

This is due today, please help!!! I will give brainliest.

WINSTONCH [101]

Answer:

Step 1, all the exponents are increased by 4

Step-by-step explanation:

The first incorrect step occurred in Step 1, where all the exponents were increased by 4.

This is mathematically incorrect due to exponential rules. When distributing exponents inside parentheses, we have to multiply the existing exponents inside the parentheses by the exponent outside the parentheses.

For example, (x²)³ is not x²⁺³, but rather, x⁽²⁾⁽³⁾.

We multiply the exponents instead of adding them together.

Therefore, the correct Step 1 should multiply all the variables' exponents by 4.

Steps 2 and 3 are correct since we do add the exponents when multiplying exponents with the same base, and we do subtract exponents with the same base when dividing.

6 0

3 years ago

A crossover trial is a type of experiment used to compare two drugs. Subjects take one drug for a period of time and then switch

zysi [14]

Answer:

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{-0.714 -0}{\frac{1.38}{\sqrt{7}}}=-1.369$

$df=n-1=7-1=6$

$p_v =2*P(t_{(6)}$

We see that the p value is higher than the ususal significance levels commonly used of 1% or 5% so then we can conclude that we FAIL to reject the null hypothesis, and there is not enough evidence to conclude that we have a different response between the two drugs

Step-by-step explanation:

We have the following info given by the problem

Subject 1 2 3 4 5 6 7

Drug A 6 3 4 5 7 1 4

Drug B 5 1 5 5 5 2 2

x=value for drug A , y = value for drug B

x: 6 3 4 5 7 1 4

y: 5 1 5 5 5 2 2

We want to verify if the mean response differs between the two drugs then the system of hypothesis for this case are:

Null hypothesis: $\mu_y- \mu_x = 0$

Alternative hypothesis: $\mu_y -\mu_x \neq 0$

We can begin calculating the difference $d_i=y_i-x_i$ and we obtain this:

d: -1, -2, 1, 0, -2, 1, -2

Now we can calculate the mean difference

$\bar d= \frac{\sum_{i=1}^n d_i}{n}=-0.714$

Now we can find the the standard deviation for the differences, and we got:

$s_d =\sqrt{\frac{\sum_{i=1}^n (d_i -\bar d)^2}{n-1}}=1.38$

And now we can calculate the statistic given by :

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{-0.714 -0}{\frac{1.38}{\sqrt{7}}}=-1.369$

Now we can find the degrees of freedom given by:

$df=n-1=7-1=6$

We can calculate the p value, since we have a two tailed test the p value is given by:

$p_v =2*P(t_{(6)}$

We see that the p value is higher than the ususal significance levels commonly used of 1% or 5% so then we can conclude that we FAIL to reject the null hypothesis, and there is not enough evidence to conclude that we have a different response between the two drugs

7 0

3 years ago

A satellite dish is shaped like a paraboloid of revolution. The signals that emanate from a satellite strike the surface of the

allochka39001 [22]

Answer:

The receiver must be placed at a distance of 6.125 ft from the center.

Step-by-step explanation:

The dish is of parabola shape with the length of 14 feet and 2 feet deep from the center.

A parabola is a curve which is a set of all points in the plane which are at equal distance away from a given point called focus and given line called directrix.

We have to find out the point at which all the waves comes to one point where the receiver must be placed is the focus of the parabola.

The above scenario is shown in the image which can be converted in mathematical graphical representation of the parabolic curve.

The extreme two end points becomes, (-7,2) and (7,2)

The general equation for such parabola is:

x² = 4ay

where, a is the distance from the center and the focus.

Since, (7,2) satisfy the equation so,

7² = 4a×2

a = 49 /8

Thus,

The receiver must be placed at a distance of 6.125 ft from the center.

5 0

3 years ago

mark invests 8000 in an account that pays 12% interest and 2000 in one that pays 8%. if he leaves the money in the accounts for

frez [133]

mark must leave it for 5.5 months or 5 and half moths to gain 5600 in interest .

Step-by-step explanation:

Here we have , mark invests 8000 in an account that pays 12% interest and 2000 in one that pays 8%. if he leaves the money in the accounts for the same length of time, We need to find how long must he leave it to gain 5600 in interest . Let's find out:

Let mark invests 8000 in an account that pays 12% interest and 2000 in one that pays 8% for time x months , So total interest gain is 5600 i.e.

⇒ $\frac{8000(12)}{100}(x) +\frac{2000(8)}{100}(x) =5600$