<span>Solve for "x":
a/x = x/4a
---
x^2 = 4a^2
x = 2a</span>
Answer:
The sample mean is
b.3.55
The margin of error is
0.32
Step-by-step explanation:
Deep explanation about a confidence interval
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find M as such

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

The lower end of the interval is the mean subtracted by M. So it is 6.4 - 0.3944 = 6.01 hours.
The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 6.74 hours.
In this problem:
The deep explanation is not that important.
We just have to recognize that the interval has a lower end and an upper end. The distance from both the upper and the lower end to the mean is M. This means that the sample mean is the halfway point between the lower end and the upper end.
The margin of error is the distance of these two points(lower and upper end) to the mean.
In our interval
Lower end: 3.23
Upper end: 3.87
Sample mean

So the correct answer is:
b.3.55
The margin of error is
3.87 - 3.55 = 3.55 - 3.23 = 0.32
The correct answers are :
(5x)² ≥ 46
x² + 5x ≤ 46
5x² > 46
<h3>
What is Inequalities?</h3>
A statement of an order relationship—greater than, greater than or equal to, less than, or less than or equal to—between two numbers or algebraic expressions.
Here, Suppose number is x
1) The square of the product of 5 and a number is not less than 46.
Step 1
Product of 5
5x
Step 2
Square of product of 5
(5x)²
Step 3
A number is not less than 46
(5x)² ≥ 46
2) The sum of square of a number and five times that number is not more than 46
Step 1
Square of a number
x²
Step 2
Five times that number
5x
Step 3
The sum = x² + 5x
Step 4
Is not more than 46
x² + 5x ≤ 46
3) The product of 5 and the square of a number is greater than 46
Step 1
The square of a number
x²
Step 2
The product of 5
5x²
Step 3
Is greater than 46
5x² > 46
Thus, The correct answers are :
(5x)² ≥ 46
x² + 5x ≤ 46
5x² > 46
Learn more about Inequality from:
brainly.com/question/20383699
#SPJ1
If the expression is: yⁿ
then y is the Base.
If the expression is: yn
then y is the product.
Answer:0.29
Step-by-step explanation:
An average of six cell phone thefts is reported in San Francisco per day. This means our mean value, u = 6
For poisson distribution,
P(x=r) = (e^-u×u^r)/r!
probability that four cell phones will be reported stolen tomorrow=
P(x=4)= (e^-6×6^4)/4!
= (0.00248×1296)/4×3×2×1
= 3.21408/24=
0.13392
P(x=5)= (e^-6×6^5)/5!
= (0.00248×7776)/5×4×3×2×1
= 19.28448/120
= 0.1607
probability that four or five cell phones will be reported stolen tomorrow
= P(x=4) + P(x=5)
= 0.13392 + 0.1607
= 0.294624
Approximately 0.29