Hi there!
Let's start by replacing "a number" by the letter "x" so that we can do an equation and isolate "x" to find your answer :
(x - ) + = -7
subtract on each side of the equation
x - = -8.25
add on each side of the equation
x = -7.5
-7.5 - 3/4 = -8.25
-8.25 + 5/4 = <u>-7</u>
So your answer is : Three-fourths was subtracted from -7.5, and then 5/4 was added to the result. The sum was -7.
There you go! I really hope this helped, if there's anything just let me know! :)
Answer: a. 1.981 < μ < 2.18
b. Yes.
Step-by-step explanation:
A. For this sample, we will use t-distribution because we're estimating the standard deviation, i.e., we are calculating the standard deviation, and the sample is small, n = 12.
First, we calculate mean of the sample:
2.08
Now, we estimate standard deviation:
s = 0.1564
For t-score, we need to determine degree of freedom and :
df = 12 - 1
df = 11
= 1 - 0.95
α = 0.05
0.025
Then, t-score is
= 2.201
The interval will be
±
2.08 ±
2.08 ± 0.099
The 95% two-sided CI on the mean is 1.981 < μ < 2.18.
B. We are 95% confident that the true population mean for this clinic is between 1.981 and 2.18. Since the mean number performed by all clinics has been 1.95, and this mean is less than the interval, there is evidence that this particular clinic performs more scans than the overall system average.
Answer:
30° each
Step-by-step explanation:
Complementary angles are those that add up to 90° so if they are all equal then it's
90/3=30°
There are a total of 297 students in the 7th grade. Rough estimates would say that about half of that number are boys and half are girls. Asking only 50 random girls would be biased because not only would it not be all of the girls (the number of girls would be around 148 or 149) but it would also be ignoring the roughly 148 to 149 boys there are on estimate. The sample would be biased because it would be ignoring the opinions of more than half the seventh grade.
Answer:
28800 minutes
Step-by-step explanation:
1 day = 24 hours
20(24) = 480 hours
1 hour = 60 minutes
480(6) = 28800 minutes