Answer:
answer : D)
Step-by-step explanation:
y – 5 ≥ 11
add 5 : y – 5 + 5 ≥ 11 + 5
y ≥ 16 ...answer : D)
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:
a. 
b. His teacher will receive more pencils (See explanation).
Step-by-step explanation:
a. The total number of pencils Louis brings to school is:
Then, in order to calculate the number of pencils Louis’s teacher will receive after he gives each of his 15 classmates an equal number of pencils, you need to solve the division show in the picture attached.
Notice that the remainder obtained is: 
.
<em>This means that Louis’s teacher will receive 4 pencils.</em>
b. If Louis decides instead to take an equal share of the pencils along with his classmates, his teacher will receive more pencils; because the amount of pencils each classmate will receive will be less. This means that the number of pencils leftover will increase, leaving more pencils for his teacher.
Answer:
- points on the boundary line: (0, 10), (20, 0)
- solution points not on the boundary line: (100, 100)
Step-by-step explanation:
We cannot tell from the posted picture whether the boundary line is solid or dashed, so the answer above is split into two parts. If the boundary line is solid (x+2y≥20), all three listed points are in the solution set. If the boundary line is dashed (x+2y>20), only (100, 100) is in the solution set.
