All categories

3 years ago

Twice the sum of a number and negative nine

Mathematics

1 answer:

Mice21 [21]3 years ago

3 0

2(x+-9)
2(x-9)
Distribute
2x-18 is the simplified expression

You might be interested in

Can anyone help please! Ixl geometry

Aliun [14]

I hope this helps you

IJH~IKL

IJ/IK=JH/KL=IH/IL

2.1/2.1+0.9=2.8/x

2.1/3=2.8/x

x=2.8*3/2.1

x=4

8 0

3 years ago

50 pts!!!! Luciana's laptop has 3,000 pictures. The size of the pictures is skewed to the right, with a mean of 3.7MB and a stan

skelet666 [1.2K]

Answer:

Part A: No, you cannot.

Part B: 0.4491

Explanation:

Part A:

The mean of samples of symmetrical (bell shaped) distributions follow a normal distribution pattern.

Thus, for symmetrical distributions you can use the z-score tables to make calculations that permit calculate probabilities for particular values.

For skewed distributions, in general, the samples do not follow a normal distribution pattern, except that the samples are large.

Since a sample of 20 pictures is not large enough, the answer to this question is negative: you cannot accurately calculate the probability that the mean picture size is more than 3.8MB for an SRS (skewed right sample) of 20 pictures.

Part B.

For large samples, the Central Limit Theorem will let you work with samples from skewed distributions.

Although the distribution of a population is skewed, the Central Limit Theorem states that large samples follow a normal distribution shape.

It is accepted that samples of 30 data is large enough to use the Central Limit Theorem.

Hence, you can use the z-core tables for standard normal distributions to calculate the probabilities for a random sample of 60 pictures instead of 20.

The z-score is calculated with the formula:

z-score = (value - mean/ (standard deviation).

$z=(x-\mu )/\sigma$

Here, mean = 3.7MB, value = 3.8MB, and standard deviation = 0.78MB.

Thus:

$z=(3.7M-3.8MB)/(0.78MB)=-0.128$

Then, you must use the z-score table to find the probability that the z-score is greater than - 0.128.

There are tables that show the cumulative probability in the right end and tables that show the cumulative probability in the left end of a normal standard distribution .

The probability that a z-score is greater than -0.128 is taken directly from a table with the cumulative probability in the left end. It is 0.4491.

4 0

3 years ago

If a parallelogram has an area of 289 meters sq and length of 17 meters what is the height

navik [9.2K]

The height would be 17 meters because,
17x17=289

4 0

3 years ago

Whoever gets the specific and correct answer will get Brainlist. Goooood luckkk <3

Elena-2011 [213]

Answer:

$6 per hour