The midpoint of a segment with endpoint (8, a) and (b, 4) is (−1, −1).

The product of two rational numbers is 6. If one of the number is 14/3, find the other number.

anastassius [24]

2=]}+]^\£\!\!\!\£\€\-6$:&2/$$/

6 0

3 years ago

Phonics is an instructional method in which children are taught to connect sounds with letters or groups of letters. A sample of

Fantom [35]

Answer:

A 90% confidence interval for the mean number of letter sounds identified in one minute is: (30.84, 37.34).

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.05 = 0.95$ , so Z = 1.645.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 1.645\frac{23.44}{\sqrt{141}}$

$M = 3.25$

The lower end of the interval is the sample mean subtracted by M. So it is 34.09 - 3.25 = 30.84.

The upper end of the interval is the sample mean added to M. So it is 34.09 + 3.25 = 37.34.

A 90% confidence interval for the mean number of letter sounds identified in one minute is: (30.84, 37.34).

6 0

3 years ago

A plane takes off from an airport and flies at a speed of 400km/h on a course of 120° for 2 hours. the plane then changes its co

butalik [34]

Answer:

Distance from the airport = 894.43 km

Step-by-step explanation:

Displacement and Velocity

The velocity of an object assumed as constant in time can be computed as

$\displaystyle \vec{v}=\frac{\vec{x}}{t}$

Where $\vec x$ is the displacement. Both the velocity and displacement are vectors. The displacement can be computed from the above relation as

$\displaystyle \vec{x}=\vec{v}.t$

The plane goes at 400 Km/h on a course of 120° for 2 hours. We can compute the components of the velocity as

$\displaystyle \vec{v_1}=$

$\displaystyle \vec{v_1}=\ km/h$

The displacement of the plane in 2 hours is

$\displaystyle \vec{x_1}=\vec{v_1}.t_1=.(2)$

$\displaystyle \vec{x_1}=km$

Now the plane keeps the same speed but now its course is 210° for 1 hour. The components of the velocity are

$\displaystyle \vec{v_2}=$

$\displaystyle \vec{v_2}=km/h$

The displacement in 1 hour is

$\displaystyle \vec{x_2}=\vec{v_2}.t_2=.(1)$

$\displaystyle \vec{x_2}=km$

The total displacement is the vector sum of both

$\displaystyle \vec{x_t}=\vec{x_1}+\vec{x_2}=+$

$\displaystyle \vec{x_t}=km$

$\displaystyle \vec{x_t}=$

The distance from the airport is the module of the displacement:

$\displaystyle |\vec{x_t}|=\sqrt{(-746.41)^2+492.82^2}$

$\displaystyle |\vec{x_t}|=894.43\ km$

8 0

3 years ago

Mrs.Kearns bought 1.5 pounds of ground beef from kroger. She paid a total of 6 .75 for the ground beef. what was the price per p

Elenna [48]

Answer:

$4.50

Step-by-step explanation:

$6.75 divided by 1.5 equals $4.50

6 0

2 years ago

Read 2 more answers

Usain Bolt ran the 2012 Olympic 100-meter race in 9.63 seconds. If he runs at this rate on a road with a speed limit of 25 miles

djverab [1.8K]

Answer:

3874.5342

Step-by-step explanation:

9.63 divide by 100 = 0.0963

0.0963x40 234= 3874.5342

6 0

3 years ago

Read 2 more answers