Which is NOT an arithmetic sequence

If kendal payed $2,500 down and $150 each month for dealer one and at another dealer paid $3,000 down and $125 each month after

maxonik [38]

After 20 months. after 20 months the first dealer will cost 5500 and the second dealer will cost 5500
dealer one pays 3000 in monthly fines and 2500 down and dealer 2 pays 2500 in fines and 300 down

6 0

2 years ago

Suppose that the national average for the math portion of the College Board's SAT is 515. The College Board periodically rescale

nasty-shy [4]

Answer:

a) 16% of students have an SAT math score greater than 615.

b) 2.5% of students have an SAT math score greater than 715.

c) 34% of students have an SAT math score between 415 and 515.

d) $Z = 1.05$

e) $Z = -1.10$

Step-by-step explanation:

To solve this question, we have to understand the normal probability distribution and the empirical rule.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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.

Empirical rule

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

$\mu = 515, \sigma = 100$

(a) What percentage of students have an SAT math score greater than 615?

615 is one standard deviation above the mean.

68% of the measures are within 1 standard deviation of the mean. The other 32% are more than 1 standard deviation from the mean. The normal probability distribution is symmetric. So of those 32%, 16% are more than 1 standard deviation above the mean and 16% more then 1 standard deviation below the mean.

So, 16% of students have an SAT math score greater than 615.

(b) What percentage of students have an SAT math score greater than 715?

715 is two standard deviations above the mean.

95% of the measures are within 2 standard deviations of the mean. The other 5% are more than 2 standard deviations from the mean. The normal probability distribution is symmetric. So of those 5%, 2.5% are more than 2 standard deviations above the mean and 2.5% more then 2 standard deviations below the mean.

So, 2.5% of students have an SAT math score greater than 715.

(c) What percentage of students have an SAT math score between 415 and 515?

415 is one standard deviation below the mean.

515 is the mean

68% of the measures are within 1 standard deviation of the mean. The normal probability distribution is symmetric, which means that of these 68%, 34% are within 1 standard deviation below the mean and the mean, and 34% are within the mean and 1 standard deviation above the mean.

So, 34% of students have an SAT math score between 415 and 515.

(d) What is the z-score for student with an SAT math score of 620?

We have that:

$\mu = 515, \sigma = 100$

This is Z when X = 620. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{620 - 515}{100}$

$Z = 1.05$

(e) What is the z-score for a student with an SAT math score of 405?

We have that:

$\mu = 515, \sigma = 100$

This is Z when X = 405. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{405 - 515}{100}$

$Z = -1.10$

3 0

3 years ago

China was isolated because of

konstantin123 [22]

Answer:

The geography of China isolated it from other cultures because there were the Himalayan Mountains, the Tibet-Qinghai Plateau, the Taklimakan Desert, and the Gobi Desert

7 0

2 years ago

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How are key features of a linear function identified and interpreted from a table, equation, and description?

Morgarella [4.7K]

Answer:

y=mx+b

Step-by-step explanation:

4 0

3 years ago

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Prove that x-s-t is a factor of x^3 - s^3 -t^3 -3st(s+t)

inessss [21]

1. Introduction. This paper discusses a special form of positive dependence. Positive dependence may refer to two random variables that have a positive covariance, but other definitions of positive dependence have been proposed as well; see [24] for an overview. Random variables X = (X1, . . . , Xd) are said to be associated if cov{f(X), g(X)} ≥ 0 for any two non-decreasing functions f and g for which E|f(X)|, E|g(X)|, and E|f(X)g(X)| all exist [13]. This notion has important applications in probability theory and statistical physics; see, for example, [28, 29]. However, association may be difficult to verify in a specific context. The celebrated FKG theorem, formulated by Fortuin, Kasteleyn, and Ginibre in [14], introduces an alternative notion and establishes that X are associated if ∗ SF was supported in part by an NSERC Discovery Research Grant, KS by grant #FA9550-12-1-0392 from the U.S. Air Force Office of Scientific Research (AFOSR) and the Defense Advanced Research Projects Agency (DARPA), CU by the Austrian Science Fund (FWF) Y 903-N35, and PZ by the European Union Seventh Framework Programme PIOF-GA-2011-300975. MSC 2010 subject classifications: Primary 60E15, 62H99; secondary 15B48 Keywords and phrases: Association, concentration graph, conditional Gaussian distribution, faithfulness, graphical models, log-linear interactions, Markov property, positive

8 0

3 years ago