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antoniya [11.8K]
2 years ago
12

Billy and Maria mow lawns. Billy earned $15 the first day and $20 every day after that. Maria earned $10 the first day and $25 e

very day after that. Find how much each earns after 15 days. How do Billy's earnings compare to Maria's?
Mathematics
1 answer:
Otrada [13]2 years ago
8 0

Answer:

Step-by-step explanation:

Billy and Maria mow lawns. Billy earned $15 the first day and $20 every day after that. This means the if Billy mowed lawns for x days after the first day, the total amount earned by Billy would be

15 + 20x

Maria earned $10 the first day and $25 every day after that. This means the if Maria mowed lawns for y days after the first day, the total amount earned by Maria would be

10 + 25y

To determine how much each earns after 15 days, it becomes

For Billy, x = 15

Amount earned = 15 + 20×15 = $315

For Maria, y = 15

Amount earned = 10 + 25×15 = $385

Maria earns more than Billy

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What is the measure (in degrees) of the smallest interior angle of a triangle in which the exterior angle measures have the rati
steposvetlana [31]

Let

3x----> angle exterior 1

4x----> angle exterior 2

5x----> angle exterior 3


we know that

The exterior angles of any polygon add up to 360 degrees

so

3x+4x+5x=360-------> 12x=360----------> x=30°


The largest of exterior angles is equal to the smallest of interior angles

so

the largest of exterior angles is 5x------> 5*30=150°

the smallest of interior angles is 180°-150°=30°


therefore


the answer is

the smallest of interior angle measure 30 degrees

8 0
2 years ago
Read 2 more answers
Assume the blood pressures of 10 people were measured before and after sleeping for the night. What is the corresponding critica
NeX [460]

Answer:

For the critical value we need to calculate the degrees of freedom given by:

df = n-1= 10-1=9

And since we have a one tailed test we need to look in the t distribution with 9 degrees of freedom a quantile who accumulates 0.05 of the area on a tail and we got:

|t_{crit}| =1.833

Step-by-step explanation:

Previous concepts

A paired t-test is used to compare two population means where you have two samples in which observations in one sample can be paired with observations in the other sample. For example if we have Before-and-after observations (This problem) we can use it.  

Let put some notation  

x=test value with right arm , y = test value with left arm  

The system of hypothesis for this case are:  

Null hypothesis: \mu_y- \mu_x = 0  

Alternative hypothesis: \mu_y -\mu_x \neq 0  

The first step is calculate the difference d_i=y_i-x_i

The second step is calculate the mean difference  

\bar d= \frac{\sum_{i=1}^n d_i}{n}= \frac{361}{5}  

The third step would be calculate the standard deviation for the differences, and we got:  

s_d =\frac{\sum_{i=1}^n (d_i -\bar d)^2}{n-1}  

The 4 step is calculate the statistic given by :  

t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}  

For the critical value we need to calculate the degrees of freedom given by:

df = n-1= 10-1=9

And since we have a one tailed test we need to look in the t distribution with 9 degrees of freedom a quantile who accumulates 0.05 of the area on a tail and we got:

|t_{crit}| =1.833

5 0
2 years ago
A researcher is estimating the mean income of residents in a large city. The income variable is usually skewed to the right. She
Gnom [1K]

Answer: We are 95% confident that the mean income for all residents of this city is between $26700 and $35400.

Step-by-step explanation:

We know that a 95% confidence interval given an interval of values that we can be 95% sure , that it contains the true mean of the population, not 95% of data lies in it.

Given : A researcher is estimating the mean income of residents in a large city. The income variable is usually skewed to the right. She collects a random sample of 25 people.

The resulting 95% confidence interval is ($26700, $35400).

Then, valid conclusion will be :  We are 95% confident that the mean income for all residents of this city is between $26700 and $35400.

5 0
2 years ago
Solve for x showing work
natali 33 [55]
X = 112
See attachment file below.

Hope it helped!

5 0
2 years ago
3.<br> The perimeter of a square garden is 12 km. Find its area.
7nadin3 [17]

Answer:

the area of the garden is 9 square kilometers

Step-by-step explanation:

4s=12

s=3

A= 3*3 = 9

3 0
2 years ago
Read 2 more answers
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