Check the picture below.
well, it's noteworthy to say that when dropping a perpendicular line from a right angle in a right triangleto the hypotenuse, we'd end up with 3 similar triangles, a Large a Medium and a Small one, all three similar.
3a)
is the Small similar to the Large one? well, let's notice, they both have a 90° angle and also they share the purple one, similar triangles by AA.
3b)
are the Medium and the Large one similar? well, let's notice, just like before, they both have a 90° and they also share the green one, similarity by AA.
3c)
are the Small and Medium similar?
if Large ~ Medium
and
Large ~ Small
then
Medium ~ Small.
In this question, it is given that
A certain bacteria culture grows at a rate of 18% everyday. There are currently 420 bacteria.
And we have to find number of bacterias on day *.
For that we use the following formula
Substituting these values in the formula, we will get
THerefore on day 8, number of bacterias are 1579.
Answer:
P(939.6 < X < 972.5) = 0.6469
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
CNNBC recently reported that the mean annual cost of auto insurance is 965 dollars. Assume the standard deviation is 113 dollars.
This means that
Sample of 57:
This means that
Find the probability that a single randomly selected policy has a mean value between 939.6 and 972.5 dollars.
This is the pvalue of Z when X = 972.5 subtracted by the pvalue of Z when X = 939.6. So
X = 972.5
By the Central Limit Theorem
has a pvalue of 0.6915
X = 939.6
has a pvalue of 0.0446
0.6915 - 0.0446 = 0.6469
So
P(939.6 < X < 972.5) = 0.6469