Answer:
The 95% confidence interval for the average number of units that students in their college are enrolled in is between 11.7 and 12.5 units.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution 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 = 45 - 1 = 44
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 44 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2
The margin of error is:
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 12.1 - 0.4 = 11.7 units
The upper end of the interval is the sample mean added to M. So it is 12.1 + 0.4 = 12.5 units
The 95% confidence interval for the average number of units that students in their college are enrolled in is between 11.7 and 12.5 units.
1.
The base can't be negative, therefore 
.
2.
3.
<u>Answer:</u>
The answer is A) y = -7x - 7.
<u>Step-by-step explanation:</u>
First, you need to subtract '7x' from both sides, and once that is done, the equation is in slope-intercept form because it is in y=mx+b form. I'll attach a photo below that explains my process! :) And another possible answer would be y = 7x + 7, but that is not an option listed above.
<em>Hope this helps! Feel free to give me Brainliest if you feel this helped. Have a good day, and good luck on your assignment. :)</em>
<h3>Answers:</h3>
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Explanation:
x = number of seconds that elapse
y = altitude (aka height) of the plane
The equation for plane A is
y = 20.25x+2652
because it starts off at 2652 ft in the air, and then adds on 20.25 feet per second which is what the 20.25x describes
The equation for plane B is
y = 75.5x
The y intercept is zero because plane B starts on the ground, aka height 0.
------------------
The system of equations is
If we want to know when they'll reach the same height (y), then we can set the two right hand sides equal to each other and solve for x.
75.5x = 20.25x+2652
75.5x-20.25x = 2652
55.25x = 2652
x = (2652)/(55.25)
x = 48
The two planes reach the same altitude at exactly <u>48 seconds</u>
That altitude is <u>3624 feet</u> because
- y = 20.25*x + 2652 = 20.25*48+2652 = 3624
- y = 75.5*x = 75.5*48 = 3624
Notice I plugged x = 48 into each equation and I got the same y value of y = 3624. This helps confirm the answers.
Answer:
Step-by-step explanation:
If J can paint a room in 3 hours, in 1 hour she gets 
of the job done.
If A can paint a room in 4 hours, in 1 hour she gets 
of the job done. We need to find out how long it takes them if they paint together. The equation for this is:
where x is the number of hours it takes them to get the job done together. Multiply everything through by 12x to get
4x + 3x = 12 so
7x = 12 and
x = 1.7 hours to get the room painted together.
