1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
denpristay [2]
2 years ago
7

Nachelle is 1.45 meters tall. At 11 a.m., she measures the length of a tree's shadow to be 23.05 meters. She stands 18.9 meters

away from the tree, so that the tip of her shadow meets the tip of the tree's shadow. Find the height of the tree to the nearest hundredth of a meter.
Mathematics
1 answer:
GREYUIT [131]2 years ago
5 0

Step-by-step explanation:

this creates 2 similar triangles.

that means all angles are the same. and all the side lengths of one triangle correlate to the corresponding side lengths of the other triangle by the same multiplication factor.

her shadow is 23.05 - 18.9 = 4.15 m long.

the factor between the shadow lengths is then

4.15 × f = 23.05

f = 23.05 / 4.15 = 5.554216867...

the same factor now applies to the relation of the heights :

1.45 × 5.554216867... = 8.053614458... m

rounded the tree is 8.05 m tall.

You might be interested in
1/4 divided by 3 solve by using tape diagram
docker41 [41]
Reduce the expression if possible, by canceling the common factor the answer is 1/12 and the decimal form would be 0.083 hope i helped
5 0
3 years ago
Solve 2x + 5y = −13 3x − 4y = −8
zlopas [31]
If you would like to solve 2x + 5y = -13 and 3x - 4y = -8, you can do this using the following steps:

2x + 5y = -13       /*4
3x - 4y = -8         /*5
_______________
8x + 20y = -52
15x - 20y = -40
_______________
8x + 15x + 20y - 20y = -52 - 40
23x = -92
x = -92 / 23
x = -4

<span>3x - 4y = -8 
</span>3 * (-4) - 4y = -8
-12 - 4y = -8
12 + 4y = 8
4y = 8 -12
4y = -4
y = -1

The correct result would be x = -4 and y = -1.
6 0
3 years ago
Rewrite the expression in the form 9^n<br> (9^3) (9^12)
BartSMP [9]

Answer:

{9}^{15}

Step-by-step explanation:

( {9}^{3} ) \times ( {9}^{12} ) = 9 {}^{3 + 12}  =  {9}^{15}  \\

5 0
3 years ago
Help!!!
Arlecino [84]
The answer is 30. 5/10 is equal to 15/30
5 0
3 years ago
We are conducting a hypothesis test to determine if fewer than 80% of ST 311 Hybrid students complete all modules before class.
Juli2301 [7.4K]

Answer:

z=\frac{0.881 -0.8}{\sqrt{\frac{0.8(1-0.8)}{110}}}=2.124  

Null hypothesis:p\geq 0.8  

Alternative hypothesis:p < 0.8  

Since is a left tailed test the p value would be:  

p_v =P(Z  

So the p value obtained was a very high value and using the significance level assumed \alpha=0.05 we have p_v>\alpha so we can conclude that we have enough evidence to FAIL to reject the null hypothesis.

Be Careful with the system of hypothesis!

If we conduct the test with the following hypothesis:

Null hypothesis:p\leq 0.8  

Alternative hypothesis:p > 0.8

p_v =P(Z>2.124)=0.013  

So the p value obtained was a very low value and using the significance level assumed \alpha=0.05 we have p_v so we can conclude that we have enough evidence to reject the null hypothesis.

Step-by-step explanation:

1) Data given and notation  

n=110 represent the random sample taken

X=97 represent the students who completed the modules before class

\hat p=\frac{97}{110}=0.882 estimated proportion of students who completed the modules before class

p_o=0.8 is the value that we want to test

\alpha represent the significance level

z would represent the statistic (variable of interest)

p_v{/tex} represent the p value (variable of interest)  2) Concepts and formulas to use  We need to conduct a hypothesis in order to test the claim that the true proportion is less than 0.8 or 80%:  Null hypothesis:[tex]p\geq 0.8  

Alternative hypothesis:p < 0.8  

When we conduct a proportion test we need to use the z statistic, and the is given by:  

z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}} (1)  

The One-Sample Proportion Test is used to assess whether a population proportion \hat p is significantly different from a hypothesized value p_o.

3) Calculate the statistic  

Since we have all the info requires we can replace in formula (1) like this:  

z=\frac{0.881 -0.8}{\sqrt{\frac{0.8(1-0.8)}{110}}}=2.124  

4) Statistical decision  

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.  

The significance level assumed \alpha=0.05. The next step would be calculate the p value for this test.  

Since is a left tailed test the p value would be:  

p_v =P(Z  

So the p value obtained was a very high value and using the significance level assumed \alpha=0.05 we have p_v>\alpha so we can conclude that we have enough evidence to FAIL to reject the null hypothesis.

Be Careful with the system of hypothesis!

If we conduct the test with the following hypothesis:

Null hypothesis:p\leq 0.8  

Alternative hypothesis:p > 0.8

p_v =P(Z>2.124)=0.013  

So the p value obtained was a very low value and using the significance level assumed \alpha=0.05 we have p_v so we can conclude that we have enough evidence to reject the null hypothesis.

5 0
3 years ago
Other questions:
  • Write the equation or inequality : in order to take honors level math , Lisa must have an average of 85 on her math tests. Her s
    7·1 answer
  • When the value of a dependant variable decreases at the independent variable increases the function is said to be.....
    5·1 answer
  • The ratio of number of boys to the of girls in a school is 5:7. If there are 600 students inthe school, how many girls are there
    11·1 answer
  • Help me asap please be serious
    10·2 answers
  • What faction of the girls in the class have long brown hair and green hair? 3/4 of the girls have brown hair,3/4 of the girls ha
    6·1 answer
  • Point P was rotated about the origin (0,0) by 105
    10·1 answer
  • 24 is what percent of 78?
    9·1 answer
  • 20/5 as a whole number
    11·1 answer
  • Solve pls brainliest
    14·2 answers
  • Questions flash
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!