Help me please I really don’t understand:(

Solve the equation x^2 – 16x + 25 = 0 to the nearest tenth.

iren [92.7K]

Answer:

1.8 and 14.3

Step-by-step explanation:

Our equation is a quadratic equation so we will use the dicriminant method

Let Δ be our dicriminant
a=1
b= -16
c= 25
Δ= (-16)²-4*25*1=156≥0
so we have two solutions : x and y
x= (16- $\sqrt{156}$ )/2= 1.7555≈ 1.8
y=(16+ $\sqrt{156}$ )/2=14.244≈ 14.3

5 0

3 years ago

Trapezoid JKLM is shown on the coordinate plane below: Trapezoid JKLM on the coordinate plane with ordered pairs at J negative 7

Arisa [49]

The answer is (6, -8). You add 8 to the x coordinate of vertex L and subtract 3 from its y coordinate.

6 0

4 years ago

Read 2 more answers

A sample of 200 observations from the first population indicated that X1 is 170. A sam- ple of 150 observations from the second

nikitadnepr [17]

Answer:

a. If the P-value is smaller than the significance level, the null hypothesis is rejected.

b. Pooled proportion = 0.8

c. z = 2.7

d. As the P-value (0.0072) is smaller than the significance level (0.05), the null hypothesis is rejected.

There is enough evidence to support the claim that the proportions differ significantly.

Step-by-step explanation:

This is a hypothesis test for the difference between proportions.

We will use the P-value approach, so the decision rule is that if the P-value is lower than the significance level, the null hypothesis is rejected.

The claim is that the proportions differ significantly.

Then, the null and alternative hypothesis are:

$H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2\neq 0$

The significance level is 0.05.

The sample 1, of size n1=200 has a proportion of p1=0.85.

$p_1=X_1/n_1=170/200=0.85$

The sample 2, of size n2=150 has a proportion of p2=0.7333.

$p_2=X_2/n_2=110/150=0.7333$

The difference between proportions is (p1-p2)=0.1167.

$p_d=p_1-p_2=0.85-0.7333=0.1167$

The pooled proportion, needed to calculate the standard error, is:

$p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{170+110}{200+150}=\dfrac{280}{350}=0.8$

The estimated standard error of the difference between means is computed using the formula:

$s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.8*0.2}{200}+\dfrac{0.8*0.2}{150}}\\\\\\s_{p1-p2}=\sqrt{0.0008+0.00107}=\sqrt{0.00187}=0.0432$

Then, we can calculate the z-statistic as:

$z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{0.1167-0}{0.0432}=\dfrac{0.1167}{0.0432}=2.7$

This test is a two-tailed test, so the P-value for this test is calculated as (using a z-table):

$P-value=2\cdot P(z>2.7)=0.0072$

As the P-value (0.0072) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the proportions differ significantly.

6 0

3 years ago

Can anyone help?? I don't understand.

Andrews [41]

If the height and base are equal, that simply means that b = h, or h = b

and we know the area is 18 m²

$\bf \textit{area of a triangle}\\\\
A=\cfrac{1}{2}bh\qquad 
\begin{cases}
b=h\\
A=18
\end{cases}\implies 18=\cfrac{1}{2}\cdot h\cdot h\implies 18=\cfrac{h^2}{2}
\\\\\\
36=h^2\implies \sqrt{36}=h$

6 0

4 years ago

Help me pls I’ve been posting this question all day

Rama09 [41]

Answer:

19.5 sq. inches

Step-by-step explanation:

This one is fairly simple. The area of a rhombus is the same as that of a parallelogram, which is side * height. In this case, we have 6.5 (side) *3 (height) = 19.5 sq. inches. Hope this helps!

6 0

3 years ago