Answer:
P = 0.006
Step-by-step explanation:
Given
n = 25 Lamps
each with mean lifetime of 50 hours and standard deviation (SD) of 4 hours
Find probability that the lamp will be burning at end of 1300 hours period.
As we are not given that exact lamp, it means we have to find the probability where any of the lamp burning at the end of 1300 hours, So we have
Suppose i represents lamps
P (∑i from 1 to 25 (
> 1300)) = 1300
= P(
> 
) where represents mean time of a single lamp
= P (Z> 
) Z is the standard normal distribution which can be found by using the formula
Z = Mean Time () - Life time of each Lamp (50 hours)/ (SD/
)
Z = (52-50)/(4/
) = 2.5
Now, P(Z>2.5) = 0.006 using the standard normal distribution table
Probability that a lamp will be burning at the end of 1300 hours period is 0.006
D)300% because it is an increase so you'd do 240/80=3•100=300
Answer:
The correct answer is:
the amount of difference expected just by chance (b)
Step-by-step explanation:
Standard error in hypothesis testing is a measure of how accurately a sample distribution represents a distribution by using standard deviation. For example in a population, the sample mean deviates from the actual mean, the mean deviation is the standard error of the mean, showing the amount of difference between the sample mean and the actual mean, occurring just by chance. Mathematically standard error is represented as:
standard error = (mean deviation) ÷ √(sample size).
standard error is inversely proportional to sample size. The larger the sample size, the smaller the standard error, and vice versa.
Answer: they’re both 53
Step-by-step explanation:
i just took the test and it is correct
