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3 years ago

Help please I’m stuck

Mathematics

1 answer:

Liono4ka [1.6K]3 years ago

3 0

Answer:

10.5

Step-by-step explanation:

ΔXYZ is similar to ΔABC. So the corresponding sides are proportional:

XY / AB = XZ / AC = YZ / BC

We want to find length AB, so we can either use the first proportion:

7 / k = 3 / 4.5

Or we can use the second proportion:

7 / k = 6 / 9

Either way, we'll get the same answer. I'll use the second proportion. Cross multiplying:

6k = 63

Dividing:

k = 10.5

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PLEASE HELPPPP Prove That: 5^31–52^9 is divisible by 100. do it like _____*100

Andru [333]

Answer:

5^31

Step-by-step explanation:

10052^9

This should be correct

8 0

2 years ago

A sample with a mean of m = 40 and a variance of s2 = 20 has an estimated standard error of 1 point. how many scores are in the

tamaranim1 [39]

The correct option is 20.

The score found for the sample is 20.

<h3>What is Standard error?</h3>

A standard error is a statistic that is applied to test the distribution of data. This metric is comparable to standard deviation. We can calculate the standard error if we know the sample size & standard deviation. It assesses the mean's precision.

Now, according to the question;

Sample mean; $\bar{x}=40$

Sample variance; $s^{2}=20$

Thus, $s=\sqrt{20}=4.47$

Standard error SE = 1

The amount of scores with in sample must be determined here.

The standard error formula is as follows:

$S E=\frac{s}{\sqrt{n}}$

We might rearrange the formula as follows:

$\begin{aligned}\sqrt{n} &=\frac{s}{S E} \\n &=\left(\frac{s}{S E}\right)^{2}\end{aligned}$

Substituting the values;

$\begin{aligned}&n=\left(\frac{4.47}{1}\right)^{2} \\&n=19.98\end{aligned}$

The sample's number of scores n = 19.98 = 20 (round up)

Therefore, the scores are in the sample is 20.

To know more about the Standard error, here

brainly.com/question/14467769

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3 0

1 year ago

Kris wanted to understand whether students at her school were in favor of an extended school day. She surveyed some students and

puteri [66]

the table below:

Grade In favor Opposed Undecided Total

Grade 9 6 4 8 18

Grade 10 10 11 9 30

Grade 11 12 15 11 38

Grade 12 15 6 14 35

If the principal randomly selects a student in grade 10 from this survey,

the probability that the student is opposed to extending the school day

P ( student in grade 10 is opposed)= Number of student in opposed(grade10) / total number of students in grade 10

Number of student opposed who is in grade10 = 11

total number of students in grade 10 = 30

P( student in grade 10 is opposed)= $\frac{11}{30}$

= 0.37

the probability that the student is opposed to extending the school day= 0.37

5 0

2 years ago

I have a spinner that is divided into 4 equal sections colored red, blue ,green, and yellow . If I spin the spinner twice ,What

Vladimir [108]

Answer:

1/16

Step-by-step explanation:

(1/4) (1/4)

7 0

2 years ago

Someone pls help me with this question

Degger [83]

Answer:

volume=0.000064 $m^{3}$

mass=0.5888kg

Step-by-step explanation:

4 0

2 years ago