Can you please help?

A rectangle has an area of 120cm2. It's length and width are whole numbers.

prohojiy [21]

The two numbers can be any factors of 120. This includes: (1,120) (2,60)(3,40)(4,30)(5,24)(6,20)(8,15)(10,12) and the reverse of this. The smallest perimeter would be the two numbers that are closer together, which is 10 and 12.

7 0

2 years ago

Crop researchers plant 15 plots with a new variety of corn. The yields in bushels per acre are: 138.0 139.1 113.0 132.5 140.7 10

son4ous [18]

There is a relationship between confidence interval and standard deviation:
$\theta=\overline{x} \pm \frac{z\sigma}{\sqrt{n}}$
Where $\overline{x}$ is the mean, $\sigma$ is standard deviation, and n is number of data points.
Every confidence interval has associated z value. This can be found online.
We need to find the standard deviation first:
$\sigma=\sqrt{\frac{\sum(x-\overline{x})^2}{n}$
When we do all the calculations we find that:
$\overline{x}=123.8\\ \sigma=11.84$
Now we can find confidence intervals:
$($90\%,z=1.645): \theta=123.8 \pm \frac{1.645\cdot 11.84}{\sqrt{15}}=123.8 \pm5.0\\($95\%,z=1.960): \theta=123.8 \pm \frac{1.960\cdot 11.84}{\sqrt{15}}=123.8 \pm 5.99\\ ($99\%,z=2.576): \theta=123.8 \pm \frac{2.576\cdot 11.84}{\sqrt{15}}=123.8 \pm 7.87\\$
We can see that as confidence interval increases so does the error margin. Z values accociated with each confidence intreval also get bigger as confidence interval increases.
Here is the link to the spreadsheet with standard deviation calculation:
https://docs.google.com/spreadsheets/d/1pnsJIrM_lmQKAGRJvduiHzjg9mYvLgpsCqCoGYvR5Us/edit?usp=sharing

6 0

3 years ago

Test scores: Scores on a statistics exam had a mean of 75 with a standard deviation of 5. Scores on a calculus exam had a mean o

beks73 [17]

Answer:

CV for statistics exam = 15%

CV for calculus exam = 19%

Since the CV for calculus exam is higher, it has a greater spread relative to the mean than the statistics exam.

Step-by-step explanation:

To find coefficient variation we use the formula:

CV = (SD/mean) * 100

CV for the statistics exam:

where; SD= 5

mean= 75

CV = ( 5/75) *100

= 0.15 or 15%

CV for calculus exam

SD = 11

Mean= 58

CV= (11 /58) * 100

= 0.19 or 19%

8 0

3 years ago

Please tell me the answer as simple as you can

dalvyx [7]

Answer:

9 lol

Step-by-step explanation:

sun of 4 and 5 is 9

difference between 8 and 7 is 9

multiply 9 by 1

5 0

3 years ago

Tristan is working on dilating rectangles. Rectangle ABCD is dilated by a factor of 3. The resulting rectangle WXYZ has an area

zloy xaker [14]

Answer:

Tristan is correct, because he needs to find the possible dimensions for rectangle WXYZ and then divide each dimension by 3.

Step-by-step explanation:

The rectangle ABCD is dilated by a factor of 3 to get the rectangle WXYZ whose area is found to be 72 cm².

Let the dimensions of the dilated rectangle WXYZ are a cm by b cm.

So, ab = 72 ........... (1)

Now, the dimensions of the original rectangle are 3 times lesser than the dimensions of rectangle WXYZ.

So, the area of rectangle ABCD will be $(\frac{a}{3} \times \frac{b}{3}) = \frac{ab}{9} = \frac{72}{9} = 8$ cm² {from equation (1)}

Therefore, Tristan is correct, because he needs to find the possible dimensions for rectangle WXYZ and then divide each dimension by 3. (Answer)

8 0

3 years ago