Answer:
Step-by-step explanation:
Solve the system of inequalities:
x + 4 < 0
OR:
6x > -12
The first inequality yields the solution:
x < -4
The second inequality gives the solution:
x > -2
The total solution is the disjunction of the individual solutions, i.e., the union of both.
It can be expressed as
Hey,
The lower quartile is the median of the lower half of the data set.
The median is the middle most number or the average of the two middle most numbers depending on how many values there are.
Cheers,
Izzy
The question is incomplete! Complete question along with answer and step by step explanation is provided below.
Question:
The lifetime (in hours) of a 60-watt light bulb is a random variable that has a Normal distribution with σ = 30 hours. A random sample of 25 bulbs put on test produced a sample mean lifetime of = 1038 hours.
If in the study of the lifetime of 60-watt light bulbs it was desired to have a margin of error no larger than 6 hours with 99% confidence, how many randomly selected 60-watt light bulbs should be tested to achieve this result?
Given Information:
standard deviation = σ = 30 hours
confidence level = 99%
Margin of error = 6 hours
Required Information:
sample size = n = ?
Answer:
sample size = n ≈ 165
Step-by-step explanation:
We know that margin of error is given by
Margin of error = z*(σ/√n)
Where z is the corresponding confidence level score, σ is the standard deviation and n is the sample size
√n = z*σ/Margin of error
squaring both sides
n = (z*σ/Margin of error)²
For 99% confidence level the z-score is 2.576
n = (2.576*30/6)²
n = 164.73
since number of bulbs cannot be in fraction so rounding off yields
n ≈ 165
Therefore, a sample size of 165 bulbs is needed to ensure a margin of error not greater than 6 hours.
Answer:
for neg its -6-6 and for the right side 8-3
Step-by-step explanation:
subtract 172000 and 8000 then divide by 2 maybe
