Answer:
where is the picture
Step-by-step explanation:
Answer:
0.75
Step-by-step explanation:
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
Answer: in 95% of races, his finishing time will be between 62 and 64 seconds.
Step-by-step explanation:
The empirical rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean . The empirical rule is further illustrated below
68% of data falls within the first standard deviation from the mean.
95% fall within two standard deviations.
99.7% fall within three standard deviations.
From the information given, the mean is 63 seconds and the standard deviation is 5 seconds.
2 standard deviations = 2 × 0.5 = 1
63 - 1 = 62 seconds
63 + 1 = 64 seconds
Therefore, in 95% of races, his finishing time will be between 62 and 64 seconds.
Answer:
x = 13
Step-by-step explanation:
Here, we want to get the missing side
from what we have, the triangle is a right angled triangle
In this kind of triangle, the Pythagoras’ theorem works
The square of the side facing the right angle ( marked x here) is equal to the sum of the squares of the two other sides
We have this as;
x^2 = 5^2 + 12^2
x^2 = 25 + 144
x^2 = 169
x = √169
x = 13
