Which best describes the error in Laura’s work

What is the answer for Chris' age and Mary's age?

Allushta [10]

Mary = M Chris = C
M = 3C-4
M-3=C+9 --> M=C+12
3C-4=C+12
2C=16
C=8
M=3C-4 --> C=8
M=3(8)-4
M=24-4
M=20

Mary is 20, and Chris is 8

5 0

3 years ago

Read 2 more answers

Triangle abc is similar to triangle FGH solve for p plebs.

12345 [234]

The value of p is 21

Step-by-step explanation:

ΔABC ~ ΔFGH

$\frac{ab}{fg} = \frac{bc}{gh} \\ \frac{35}{p} = \frac{10}{6} \\ p = \frac{35 \times 6}{10} \\ p = \frac{210}{10} \\ p = 21 \\ \\ or \\ \\ \frac{ab}{fg} = \frac{ac}{fh} \\ \frac{35}{p} = \frac{30}{18} \\ p = \frac{35 \times 18}{30} \\ p = \frac{630}{30} \\ p = 21$

So, the value of p is 21

Hope it helpful and useful :)

5 0

4 years ago

a sample of 412 adults showed that 293 of them are connected the the internet from home. Construct and interpret a 90% confidenc

Anna [14]

Answer:

CI = (0.674, 0.748)

Step-by-step explanation:

The confidence interval of a proportion is:

CI = p ± SE × CV,

where p is the proportion, SE is the standard error, and CV is the critical value (either a t-score or a z-score).

We already know the proportion:

p = 293/412

p = 0.711

But we need to find the standard error and the critical value.

The standard error is:

SE = √(p (1 − p) / n)

SE = √(0.711 × (1 − 0.711) / 412)

SE = 0.0223

To find the critical value, we must first find the alpha level and the degrees of freedom.

The alpha level for a 90% confidence interval is:

α = (1 − 0.90) / 2 = 0.05

The degrees of freedom is one less than the sample size:

df = 412 − 1 = 411

Since df > 30, we can approximate this with a normal distribution.

If we look up the alpha level in a z score table or with a calculator, we find the z-score is 1.645. That's our critical value. CV = 1.645.

Now we can find the confidence interval:

CI = 0.711 ± 0.0223 * 1.645

CI = 0.711 ± 0.0367

CI = (0.674, 0.748)

So we are 90% confident that the proportion of adults connected to the internet from home is between 0.674 and 0.748.

5 0

3 years ago

Is DEF a right triangle? True or false

umka2103 [35]

Short answer = false
Remark
If it is a right triangle, it will obey the Pythagorean Equation. a^2 + b^2 = c^2. Let's see if it does.

Equation
a^2 + b^2= c^2
c must be the longest line. (Hypotenuse)

Givens
a = 24
b = 17
c = 40

Sub and Solve
a^2 + b^2 = c^2
17^2 + 24^2 = c^2 [We'll see if this comes out to 40]

289 + 576 = c^2
865 = c^2 which is no where near what 40^2 equals. 40^2 = 1600

Short answer False

Square root of 865 = (865)^1/2 = 29.4

5 0

4 years ago

Ali, Ben, and Cliff plant seedlings in their neighborhood park. Ali plants 40% of the total number of seedlings, Ben plants 45%

Juli2301 [7.4K]

Answer:

580 seedlings altogether.

Step-by-step explanation:

Given that,

Ali plants 40% of the total number of seedlings, Ben plants 45% of the total number of seedlings, and Cliff plants the rest of the seedlings. Cliff plants 87 seedlings.

The percentage of the seedling planted by Cliff = 100% - 45% - 40% = 15%

Let x = the total number of seedlings

$15\%\ of\ x=87\\\\x=\dfrac{87\times 100}{15}\\\\x=580$

Hence, three boys plant 580 seedlings altogether.

7 0

3 years ago