How many solutions does this system have 2x + y = -1 -4x

Lerok [7]

Answer:

B) rhombus

Step-by-step explanation:

the tic marks on the lines indicate that they are congruent, not parallel there is no way of knowing for sure that those lines are parallel therefore it is not a parallelogram even though it looks like it

5 0

3 years ago

Mr. Jacobs is going to make a histogram of the test scores from the last math test he gave. He plans to first organize the data

lukranit [14]

The stem and leaf plot will look like:
6 | 1 5 8 - 3 scores
7 | 1 7 7 9 - 4 scores
8 | 2 3 4 5 7 9 - 6 scores
9 | 0 1 4 7 9 - 1 score
To total up the number of students who scored less than 90, we have 3 under 60-69, 4 under 70-79, and 6 under 80-89, so this is 3 + 4 + 6. This is the third choice.

8 0

3 years ago

Find the approximate length of the track, including the straight and circular sections

puteri [66]

Answer:

mannn u figure it out

Step-by-step explanation:

6 0

2 years ago

Suppose that in one region of the country the mean amount of credit card debt perhousehold in households having credit card debt

kvv77 [185]

Answer:

The probability that the mean amount of credit card debt in a sample of 1600 such households will be within $300 of the population mean is roughly 0.907 = 90.7%.

Step-by-step explanation:

To solve this question, we have to understand the normal probability distribution and the central limit theorem.

Normal probability distribution:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central limit theorem:

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$

In this problem, we have that:

$\mu = 15250, \sigma = 7125, n = 1600, s = \frac{7125}{\sqrt{1600}} = 178.125$

The probability that the mean amount of credit card debt in a sample of 1600 such households will be within $300 of the population mean is roughly

This probability is the pvalue of Z when X = 1600 + 300 = 1900 subtracted by the pvalue of Z when X = 1600 - 300 = 1300. So

X = 1900

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{1900 - 1600}{178.125}$

$Z = 1.68$

$Z = 1.68$ has a pvalue of 0.9535.

X = 1300

$Z = \frac{X - \mu}{s}$

$Z = \frac{1300 - 1600}{178.125}$

$Z = -1.68$

$Z = -1.68$ has a pvalue of 0.0465.

0.9535 - 0.0465 = 0.907.

The probability that the mean amount of credit card debt in a sample of 1600 such households will be within $300 of the population mean is roughly 0.907 = 90.7%.

7 0

3 years ago

Jane travels7 mph less than2 times as fast as Mike. Starting at the same point and traveling in the same direction, they are198

Sphinxa [80]

Let:

Vj = Speed of jane

Vm = Speed of mike

d = distance

t = time

Jane travels 7 mph less than 2 times as fast as Mike, therefore:

Vj = 2Vm - 7

Remeber:

distance = speed*time

Distance traveled by mike:

d=Vm*t = Vm*6

Distance traveled by jane:

d + 198 = Vj*6

where:

Vj = 2Vm - 7

d + 198 = (2Vm-7)*6

Now, let:

d=Vm*6 (1)

d + 198 = (2Vm-7)*6 (2)

Replace (1) into (2)

6Vm + 198 = 12Vm - 42

Subtract 6Vm from both sides:

6Vm + 198 - 6Vm = 12Vm - 42 - 6Vm

198 = 6Vm - 42

Add 42 to both sides:

198 + 42 = 6Vm - 42 + 42

240 = 6Vm

Divide both sides by 6:

240/6 = 6Vm/6

40 = Vm

Vm = 40mph

Replace Vm into this equation Vj = 2Vm - 7 :

Vj = 2(40) - 7 = 80 - 7 = 73mph

4 0

1 year ago

How many solutions does this system have 2x + y = -1 -4x - 2y = -5