What is an an expression that is equivalent to 9 ( 3x + 5 + x ) without using parentheses.

Melania has two jobs. During the day she works as an office clerk, and in the evening she works as a cashier. her office job pay

bulgar [2K]

Lets x = # of hours Melania  works at <span>office clerk
and y = </span># of hours Melania  works as a <span>cashier

x + y = 38 so x = 38 - y
13x + 9.25y = 434

substitute </span> x = 38 - y into 13x + 9.25y = 434

13x + 9.25y = 434
13(38 - y) + 9.25y = 434
494 - 13y + 9.25y = 434
-3.75y = -60
y = 16
x = 38 - y so x = 38 - 16 = 22

answer
Melania  works at office clerk = 22 hours
Melania  works as a cashier = 16 hours

7 0

2 years ago

In a study of 30 high school students, researchers found a high correlation, 0.93, between amount of exercise and weight lost. W

zloy xaker [14]

Answer:

Option A is true

The researchers proved that exercise causes weight loss only for high school students.

Step-by-step explanation:

We are told that the researchers found a high correlation, 0.93, between amount of exercise and weight lost.

Now, looking at each of the options;

- A is True because due to the high correlation, the research proves that exercise causes weight loss but only for high school students.

- B is not true because we are told the correlation is very high at 0.93. Thus, it is untrue that there is no proven causation.

-C is not true because there's no where that the researchers have completely proved that exercise causes weight loss generally. It is only peculiar to the high school students studied.

-D is not true because the 93% is just a correlation and not a percentage of those who lost weight

8 0

2 years ago

From an elevation of 3.5m below the surface of water, a northern bottlenose whale dives at a rate of 1.8 meters per section (m/s

MAVERICK [17]

Answer:

d=3.5+1.8t

Step-by-step explanation:

4 0

1 year ago

Which function models the area of a rectangle with side lengths of 2x-4 units and x+1 units?

Morgarella [4.7K]

Answer:

Step-by-step explanation:

——————————————————————————————

l

l l

l____________________________________________l

either the ____ line is 2x-4 or x+1

either the "l" line is the other eq the the _____ one

3 0

2 years ago

Of interest is to determine the mean age of students at the time they take the comprehensive exam for all students enrolled in g

Gnoma [55]

Answer:

The 98% confidence interval for the mean age of students at the time they take the comprehensive exam for all students enrolled in graduate programs that require students to take comprehensive exams is between 26.2 and 28.8 years. This means that we are 98% sure that the mean age of all students taking the exam is between 26.2 and 28.8 years.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 31 - 1 = 30

98% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 30 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.98}{2} = 0.99$ . So we have T = 2.457

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2.457\frac{2.9}{\sqrt{31}} = 1.3$

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 27.5 - 1.3 = 26.2 years

The upper end of the interval is the sample mean added to M. So it is 27.5 + 1.3 = 28.8 years

The 98% confidence interval for the mean age of students at the time they take the comprehensive exam for all students enrolled in graduate programs that require students to take comprehensive exams is between 26.2 and 28.8 years. This means that we are 98% sure that the mean age of all students taking the exam is between 26.2 and 28.8 years.

8 0

2 years ago