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3 years ago

7

How are the rules for adding and subtracting negative numbers similar to adding and subtracting positive numbers? Justify your r

esponse with an example

1 answer:

Fantom [35]3 years ago

8 0

Answer: the rules are

+(+) Two like signs become a positive sign

−(−) 6−(−3) = 6 + 3 = 9

+(−) Two unlike signs become a negative sign

−(+)

Step-by-step explanation:

Example: 3+(+2) = 3 + 2 = 5, 6−(−3) = 6 + 3 = 9, 7+(−2) = 7 − 2 = 5,8−(+2) = 8 − 2 = 6 hope this helps you :)

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Marissa deposited $3,900 into a savings account. How much will Marissa have in her account after 7 years and 6 months at a yearl

REY [17]

Marissa wants to know how much she would make using the simple interest calculation.

She will have $4,432.35

Given data

Principal = $3,900

Time = 7 years 6 months = 7.5 years

Rate = 1.82%

I = A - P = $532.35

Equation:

A = P(1 + rt)

Calculation:

First, converting R percent to r a decimal

r = R/100 = 1.82%/100 = 0.0182 per year.

Solving our equation:

A = 3900(1 + (0.0182 × 7.5)) = 4432.35

A = $4,432.35

The total amount accrued, principal plus interest, from simple interest on a principal of $3,900.00 at a rate of 1.82% per year for 7.5 years is $4,432.35.

Learn more about simple interest here:

brainly.com/question/20690803

3 0

2 years ago

Of the total population of American households, including older Americans and perhaps some not so old, 17.3% receive retirement

Alex Ar [27]

Answer:

47.54% probability that more than 20 households but fewer than 35 households receive a retirement income

Step-by-step explanation:

We use the binomial aproxiation to the normal to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be 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.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$p = 0.173, n = 120$ . So

$\mu = E(X) = np = 120*0.173 = 20.76$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{120*0.173*0.827} = 4.14$

In a random sample of 120 households, what is the probability that more than 20 households but fewer than 35 households receive a retirement income?

We are working with discrete values, so this is the pvalue of Z when X = 35-1 = 34 subtracted by the pvalue of Z when X = 20 + 1 = 21.

X = 34

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

$Z = \frac{34 - 20.76}{4.14}$

$Z = 3.2$

$Z = 3.2$ has a pvalue of 0.9993

X = 21

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

$Z = \frac{21 - 20.76}{4.14}$

$Z = 0.06$

$Z = 0.06$ has a pvalue of 0.5239

0.9993 - 0.5239 = 0.4754

47.54% probability that more than 20 households but fewer than 35 households receive a retirement income

6 0

3 years ago

Which one of the following would most likely have a negative linear correlation coefficient?

Alja [10]

Answer:

D

Step-by-step explanation:

RATE BRAINLIEST IF RIGHT

7 0

3 years ago

Read 2 more answers

Simplify the expression.<br><br> 7(x - 1) - 2(x + 1) + 3( x - 4) =

lawyer [7]

7x-7-2x-2+3x-12=8x-21
I think

8 0

3 years ago

Read 2 more answers

The first term of a geometric sequence is 32, and the 5th term of the sequence is 818 .

sammy [17]

Answer:

$32,24,18,\frac{27}{2} ,\frac{81}{8}$

Step-by-step explanation:

Let x, y , and z be the numbers.

Then the geometric sequence is $32,x,y,z,\frac{81}{8}$

Recall that term of a geometric sequence are generally in the form:

$a,ar,ar^2,ar^3,ar^4$

This implies that:

a=32 and $ar^4=\frac{81}{8}$

Substitute a=32 and solve for r.

$32r^3=\frac{81}{8}$

$r^4=\frac{81}{256}$

Take the fourth root to get:

$r=\sqrt[4]{\frac{81}{256} }$

$r=\frac{3}{4}$

Therefore $x=32*\frac{3}{4} =24$

$y=24*\frac{3}{4} =18$

$z=18*\frac{3}{4} =\frac{27}{2}$

8 0

3 years ago