Answer:

Step-by-step explanation:
Since the population standard deviation
is unknown, and the sample standard deviation
, must replace it, the
distribution must be used for the confidence interval.
The sample size is n=8.
The degree of freedom is
,
.
With 95% confidence level, the
(significance level) is 5%.
Hence with 7 degrees of freedom,
. (Read from the t-distribution table see attachment)
The 95% confidence interval can be found by using the formula:
.
The sample mean is
hours.
The sample sample standard deviation is
hours.
We now substitute all these values into the formula to obtain:
.

We are 95% confident that the population mean is between 26.12 and 31.48 hours.
Answer:
1.1 gigabytes
Step-by-step explanation:
Let us represent:
The number of gigabytes = g
Under his cell phone plan, Owen pays a flat cost of $67.50 per month and $4 per gigabyte. He wants to keep his bill at $71.90 per month.
The Equation is given as:
$71.90 = $67.50 + $4 × g
71.90 = 67.50 + 4g
71.90 - 67.50 = 4g
4.4 = 4g
x = 4.4/4
x = 1.1 gigabytes
Therefore, the number of gigabytes of data Owen can use while staying within his budget is 1.1 gigabytes
Answer:
Volume = 11680.44 cubic inches
Step-by-step explanation:
Circumference of the trunk of a tree = 2πr
Here, r = radius of the trunk
26π = 2πr
r = 13 inch
Since, volume of the cylindrical trunk = πr²h
= π(13)²(22)
= 3718π
= 11680.44 cubic inches
Answer: 16
Step-by-step explanation: 20/2 = 10
10x=160
10x/10=160/10
x=16
Answer:
3+12i
Step-by-step explanation:
The difference of 5+3i and 2 + 1999 can be calculated as follows
= 5+3i - 2+9i
Collect the like terms
= 5-2+3i+9i
= 3+12i
Hence the difference of 5+3i and 2+9i is 3+12i