Easy question if your having big problem
2 answers:
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Answer:
0.5352 = 53.52% probability that the sample mean would differ from the population mean by more than 0.8 millimeters
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 normally distributed samples are solved using the z-score formula.
In a set with mean and standard deviation(which is the square root of the variance)
, 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.
In this problem, we have that:
If a random sample of 38 steel bolts is selected, what is the probability that the sample mean would differ from the population mean by more than 0.8 millimeters?
Either it differs by 0.8 millimeters or less, or it differs by more than 0.8 millimeters. The sum of the probabilities of these events is 1.
Probability it differs by 0.8 millimeters or less.
pvalue of Z when X = 133 + 0.8 = 133.8 subtracted by the pvalue of Z when X = 133 - 0.8 = 132.2.
X = 133.8
By the Central Limit Theorem
has a pvalue of 0.7324
X = 132.2
has a pvalue of 0.2676
0.7324 - 0.2676 = 0.4648
0.4648 probability it differs by 0.8 millimeters or less.
Probability it differs by more than 0.8 millimeters
p + 0.4648 = 1
p = 0.5352
0.5352 = 53.52% probability that the sample mean would differ from the population mean by more than 0.8 millimeters
Answer:
Side A = 14; Side B = 24.25; Side C = 28 |
Angle A = 60 degrees; Angle B = 30 degrees; Angle C = 90 degrees
Step-by-step explanation:
Okay, I find this question a bit weird because you already have two sides
So, I'm going to assume:
Side A = 14
Side B = 24.25
<h3>Finding side C</h3>Using Pythagoras theorem
c = 28 units (28.00111605)
<h3>Finding Angles (A,B and C)</h3>In the diagram, we can see there is a right angle triangle, and a little square
Therefore, we can say that Angle C is 90 degrees
Finding Angle A/B:
There are so many ways to find it, I'll just use this though
<h3>Method: Using SOHCAHTOA to find B, then finding A</h3>Using SOHCAHTOA
I'll be using the sine rule to find Angle B
Angle B = 30 degrees
The interior angles in a triangle add up to 180 degrees
Angle A = 180 - (90 + 30)
Angle A = 60 degrees
Verify:
60 + 30 + 90 = 180