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3 years ago

I already did Number 1 I just need help on the rest:)

Mathematics

2 answers:

lord [1]3 years ago

8 0

Answer:

number 3 is 8/21

Step-by-step explanation:

EleoNora [17]3 years ago

3 0

Answer:

so the 60 people and the other 30 people want to go to like a museum so it would be 170.

Step-by-step explanation:

You might be interested in

. If a, b, c are real numbers such that ac # 0

galben [10]

Answer:

if one equation has no real roots, the other must have real roots. Hence, at least one equation has real roots.

Step-by-step explanation:

The discriminant of the first equation is ...

d1 = b^2 -4ac

The discriminant of the second equation is ...

d2 = b^2 +4ac

Suppose the first equation has no real roots. Then ...

d1 < 0

b^2 -4ac < 0

b^2 < 4ac

We know that b^2 is non-negative, so this means 4ac is positive. For that case,

d2 = b^2 +4ac

is the sum of a positive number and a non-negative number so will be positive. When the discriminant is positive, there are two real roots.

When the first equation has no real roots, the second one must have two real roots.

Suppose the second equation has no real roots. Then ...

d2 < 0

b^2 +4ac < 0

b^2 < -4ac

Again, b^2 is non-negative, so -4ac must be positive. For this case, the sum ...

d1 = b^2 -4ac

is the sum of a non-negative and a positive number, so will be positive. The positive discriminant means there are two real roots.

When the second equation has no real roots, the first one must have two real roots.

One of these equations will have real roots, or not. If not, the other must have (distinct) real roots.

7 0

3 years ago

Using traditional methods, it takes 108 hours to receive a basic driving license. A new license training method using Computer A

Rainbow [258]

Answer: z= -2.35

Step-by-step explanation:

When the population variation is know, then we calculate the z-statistic.

Formula to calculate the z-test statistic is given by :-

$z=\dfrac{\overline{x}-\mu}{\dfrac{s}{\sqrt{n}}}$

where , n= sample size

$\overline{x}$ = sample mean

$\mu$ = Population mean

$\sigma$ =Population standard deviation.

As per given we have,

n= 270

$\mu= 108$

$\overline{x}=107$

$\sigma^2=49\\\\\Rightarrow \sigma=\sqrt{49}=7$

Then, z-statistic will be

$z=\dfrac{107-108}{\dfrac{7}{\sqrt{270}}}$ (Substitute all the values )

$\Rightarrow\ z=\dfrac{-1}{\dfrac{7}{16.4316767252}}$

$\Rightarrow\ z=\dfrac{-1}{0.426006433614}$

$\Rightarrow\ z=-2.34738238931\approx-2.35$

Hence, the value of the test statistic= z= -2.35

4 0

3 years ago

Find the volume of the composite figure.First, find the volume of the cylinder.Use 3.14 for it.CylinderVolume = [?] cm9 cm9 cmCu

skad [1K]

Solution

- The question gives us a composite figure made up of a cylinder and a cube.

- We are required to find the volume of the cylinder and the cube and then use the results to find the volume of the composite figure.

- The formulas needed for this calculation are:

$\begin{gathered} Volume\text{ of Cylinder}=\pi\times r^2\times h \\ where, \\ r=radius\text{ of the cylinder} \\ h=height\text{ of the cylinder} \\ \\ Volume\text{ of Cube}=l^3 \\ where, \\ l=dimension\text{ of the cube} \\ \\ Volume\text{ of Composite figure}=Volume\text{ of Cylinder }+Volume\text{ of Cube} \\ \end{gathered}$

- With the information above, we can proceed to solve the question

Volume of the Cylinder:

$\begin{gathered} V=\pi\times r^2\times h \\ r=\frac{6}{2}=3\text{ \lparen Since 6cm is the diameter of the cylinder\rparen} \\ h=4 \\ \\ \therefore V=\pi\times3^2\times4 \\ \\ V=36\pi cm^3 \end{gathered}$

Volume of Cube: