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3 years ago

Please help (picture)

Mathematics

2 answers:

givi [52]3 years ago

3 0

A = 360 cm^2

Step-by-step explanation:

Using Pythagorean theorem, the length AB is given by

AB^2 = 17^2 - 8^2 = 225 cm^2

AB = 15 cm

Since the ratio BC: CD = 1:2 and BC = 8 cm, this means that CD = 2×(8 cm) = 16 cm

so the length BD is

BD = BC + CD = 8cm + 16 cm = 24 cm

There the area of the rectangle is

A = AB×BD

= 15cm×24cm

= 360 cm^2

Umnica [9.8K]3 years ago

3 0

The answer is 320 hop this help you for your word

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An experiment on memory was performed, in which 16 subjects were randomly assigned to one of two groups, called "Sentences" or "

FromTheMoon [43]

Answer:

There is no significant difference between the averages.

Step-by-step explanation:

Let's call

$\large X_{sentences}$ the mean of the “sentences” group

$\large S_{sentences}$ the standard deviation of the “sentences” group

$\large X_{intentional}$ the mean of the “intentional” group

$\large S_{intentional}$ the standard deviation of the “intentional” group

Then, we can calculate by using the computer

$\large X_{sentences}=28.75$

$\large S_{sentences}=3.53553$

$\large X_{intentional}=31.625$

$\large S_{intentional}=1.40788$

$\large X_{sentences}-X_{intentional}=28.75-31.625=-2.875$

The standard error of the difference (of the means) for a sample of size 8 is calculated with the formula

$\large \sqrt{(S_{sentences})^2/8+(S_{intentional})^2/8}$

So, the standard error of the difference is

$\large \sqrt{(3.53553)^2/8+(1.40788)^2/8}=1.34546$

In order to see if there is a significant difference in the averages of the two groups, we compute the interval of confidence of 95% for the difference of the means corresponding to a level of significance of 0.05 (5%).

If this interval contains the zero, we can say there is no significant difference.

Since the sample size is small, we had better use the Student's t-distribution with 7 degrees of freedom (sample size-1), which is an approximation to the normal distribution N(0;1) for small samples.

We get the $\large t_{0.05}$ which is a value of t such that the area under the Student's t distribution outside the interval $\large [-t_{0.05}, +t_{0.05}]$ is less than 0.05.