Answer:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Let X the random variable that represent interest on this case, and for this case we know the distribution for X is given by:
And let 
represent the sample mean, the distribution for the sample mean is given by:
On this case 
Solution to the problem
We want this probability:
The best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
Answer:
75%
88.89%
Step-by-step explanation:
Given :
Mean = 70
Standard deviation = 12
Since the data is said to be extremely skewed, we apply Chebyshev's theorem rather than the empirical rule :
The minimum proportion of observation between 46 and 94
Chebyshev's theorem :
1 - 1 / k²
k = number of standard deviations from the mean
k = (94 - 70) / 12 = 24 / 12 = 2
Hence, we have ;
1 - 1/2²
1 - 1/4
1 - 0.25 = 0.75
Hence, The minimum proportion of observation between 46 and 94 is 75%
Between 36 and 106 :
k = (106 - 70) / 12 ;
k = 36/12 = 3
Hence,
1 - 1/3² = 1 - 1/9 = 8/9 = 0.8888 = 88.89%
The minimum proportion of observation between 34 and 106 is 88.89%
Answer:
143
Step-by-step explanation:
lets make a fraction:
so
91 oil changes/7days
lets take "x" as the unknown # of oil changes:
so
x/11
91/7=x/11
we can cross multiply:
91*11=7*x
1001=7x
143=x
so 143 oil changes in 11 days
Hope this helps!
Answer:
the value of x to the nearest tenth is 12 * x
Answer:
The missing statement is ∠ACB ≅ ∠ECD
Step-by-step explanation:
Given two lines segment AC and BD bisect each other at C.
We have to prove that ΔACB ≅ ΔECD
In triangle ACB and ECD
AC=CE (Given)
BC=CD (Given)
Now to prove above two triangles congruent we need one more side or angle
so, as seen in options the angle ∠ACB ≅ ∠ECD due to vertically opposite angles
hence, the missing statement is ∠ACB ≅ ∠ECD
