9514 1404 393
Answer:
13
Step-by-step explanation:
The distance between the points is the magnitude of their difference.
|(-2-3i) -(3+9i)| = |-5 -12i| = √(5² +12²) = 13
The distance between the point is 13 units.
Answer:
Step-by-step explanation:
We want to determine a 90% confidence interval for the mean amount of time that teens spend online each week.
Number of sample, n = 41
Mean, u = 43.1 hours
Standard deviation, s = 5.91 hours
For a confidence level of 90%, the corresponding z value is 1.645. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean +/- z ×standard deviation/√n
It becomes
43.1 ± 1.645 × 5.91/√41
= 43.1 ± 1.645 × 0.923
= 43.1 ± 1.52
The lower end of the confidence interval is 43.1 - 1.52 =41.58
The upper end of the confidence interval is 43.1 + 1.52 =44.62
Therefore, with 90% confidence interval, the mean amount of time that teens spend online each week is between 41.58 and 44.62
I just don’t know what to say I look like a little bit confused lol lol
X+7= Yvonne's age.
a. 4(x+7)=200
b. 4(x+7)=200
4x+28=200
4x=172
x=43
Yvonne is 43 years old.
c. 43-7=Xavier's age.
36
Xavier is 36 years old.