The phrasing "nine times out of ten" means 9/10 = 0.90 = 90% is the confidence level. We're confident 90% of the time that the confidence interval captures the population parameter we're after (in this case mu = population mean)
The portion "have an average score within 5% of 75%" means that 75% = 0.75 is the center of the confidence interval, and it goes as low as 0.75 - 0.05 = 0.70 and as high as 0.75 + 0.05 = 0.80
This confidence interval is from 70% to 80%, meaning that nine times out of ten, we're confident that the average score is between 70% and 80%
We write the confidence interval as (0.70, 0.80). It's common to use the notation (L, U) to indicate the lower (L) and upper (U) boundaries. You might see the notation in the form L < mu < U. If so, then it would be 0.70 < mu < 0.80; either way they mean the same thing.
The margin of error is 0.05 as its the 5% radius of the interval. It tells us how far the most distant score is from the center (75%)
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In summary, we have these answers
- confidence level = 90%
- margin of error = 5% = 0.05
- confidence interval = (0.70, 0.80)
- interpretation = We're 90% confident that the average exam score is between 0.70 and 0.80
From what I got there is one real solution :)
Rearrange the second equation to give y=2-2x, substitute into the first equation to give you a value for x and then using that you can work out y for the exact coordinates of intersection :)
Also they are both straight line graphs so they will either have one or no solutions
Hope this helped :)
Answer:
a taco is 1.25 and a drink is 0.95
Step-by-step explanation:
tacos = t
drinks = d
5t + 3d = 9.10
3t + d = 4.70
this is a simultaneous equation so times the first one by one and the second by 3 and then take them away from each other and solving to get
t = 1.25 and d=0.95
one drink is $0.95
one taco is $1.25
Hope this helps!!
Answer:
All real numbers are solutions.
Step-by-step explanation:
Let's solve your equation step-by-step.
7x− 3 = − 3 + 7x
Step 1: Simplify both sides of the equation.
7x − 3 = −3 + 7x
7x + −3 = −3 + 7x
7x − 3 = 7x − 3
Step 2: Subtract 7x from both sides.
7x− 3 −7x = 7x −3 −7x
−3 = −3
Step 3: Add 3 to both sides.
−3 + 3 = −3 + 3
0 = 0
