How many 1/9make up2/3
1 answer:
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Answer:
0.4514 = 45.14% probability that the mean of the sample would differ from the population mean by less than 1 point if 60 exams are sampled
Step-by-step explanation:
To solve this question, we have 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
, 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 random variable X, with mean and standard deviation
, a large sample size can be approximated to a normal distribution with mean
and standard deviation
In this problem, we have that:
What is the probability that the mean of the sample would differ from the population mean by less than 1 point if 60 exams are sampled?
This is the pvalue of Z when X = 159+1 = 160 subtracted by the pvalue of Z when X = 159-1 = 158. So
X = 160
By the Central Limit Theorem
has a pvalue of 0.7257
X = 150
has a pvalue of 0.2743
0.7257 - 0.2743 = 0.4514
0.4514 = 45.14% probability that the mean of the sample would differ from the population mean by less than 1 point if 60 exams are sampled
Answer:
Pies=$0.85
Donuts= $1.20
Step-by-step explanation:
In the equation let p stand for the number of pies and d stand for the number of donuts.
To solve this set up 2 equations, one representing bill and the other representing Mary Ann.
- Bill's equation is 5p+7d=$12.65.
- Mary Ann's equation is 6p+6d=$12.30
Then solve using a system of equations. Systems of equations can be solved using elimination or substitution. I will use substitution. Solve bill's equation for p. This gives you . Then, you can substitute that into Mary Ann's equation. This looks like
. Solve for d. Once you solve d=1.20. Finally, substitute 1.20 back into either Bill's or Mary Ann's for d and solve for p. No matter which equation you use p=0.85.