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3 years ago

Carly beat the school record for the 400 meter run by 1.3 seconds. if she ran the race in 55.7 seconds, what was the record

1 answer:

3 0

If Carly broke the record by 1.3 seconds and Carly's time was 55.7 the old record would be Carly's time plus 1.3 seconds for the time that Carly broke the record by, so... 57 seconds was the old record

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Please help with my math assignment! Simplify, write the expression using only positive exponents.

baherus [9]

Answer:

$\frac{6}{y^4}$

Step-by-step explanation:

To evaluate or simplify expressions with exponents, we use exponent rules.

1. An exponent is only a short cut for multiplication. It simplifies how we write the expression.

2. When we multiply terms with the same bases, we add exponents.

3. When we divide terms with the same bases, we subtract exponents.

4. When we have a base to the exponent of 0, it is 1.

5. A negative exponent creates a fraction.

6. When we raise an exponent to an exponent, we multiply exponents.

7. When we have exponents with parenthesis, we apply it to everything in the parenthesis.

We will use these rules to simplify.

$6y^{-4} = \frac{6}{y^4}$

5 0

4 years ago

What are the coordinates a(-6,-8),B(-6,-2)C(-2,-2) rotated 180 degrees

Pachacha [2.7K]

Answer:

Step-by-step explanation:

first option you can try and draw aand plot them in a graph and rotate it at 180 degrees to get A(-6,8) B(-6,2) C(-2,2)

Or use the principle that when you rotate co-ordinates at 180 thye x-axis remains constant and tyhe y-axis changes its sign + to- or - to +

8 0

3 years ago

Read 2 more answers

A major manufacturing firm producing PCB for electrical insulation discharges small amounts from the plant. We assume that the a

xxTIMURxx [149]

Answer:

a. Z = 2.6667

c. Upper limit = 3.39

Step-by-step explanation:

Part a

We are given

Population mean = 3

Population standard deviation = 0.3

Sample mean = 3.2

Sample size = n = 16

Level of significance = 0.05

Null hypothesis: H0: µ = 3

Alternative hypothesis: Ha: µ > 3

The test statistic formula is given as below:

Z = (sample mean – population mean) / [SD / sqrt(n)]

Z = (3.2 – 3)/[0.3/sqrt(16)]

Z = 2.6667

Part b

Type I error is the probability of rejecting the null hypothesis that the population mean is 3 ppm when actually it is 3 ppm. Type II error is the probability of do not rejecting the null hypothesis that the population mean is 3 ppm when actually it is exceeding 3 ppm. Type II error is the serious in this scenario.

Part c

We are given

Population mean = 3

Population standard deviation = 0.3

Sample mean = 3.2

Sample size = n = 16

Confidence level = 90%

Critical z value = 2.3263

Formula is given as below:

Lower limit =sample mean – z*SD/sqrt(n)

Upper limit = sample mean + z*SD/sqrt(n)

Lower limit = 3.2 – 2.5758*0.3/sqrt(16)

Lower limit = 3.01

Upper limit = 3.2 + 2.5758*0.3/sqrt(16)

Upper limit = 3.39

6 0

3 years ago

Martha invested a principal amount of $15,000 into a savings account that earns simple interest at a rate of 4.5% per year. How

lidiya [134]

Option A

The simple interest earned over 6 years is $ 4050

Solution:

Martha invested a principal amount of $15,000 into a savings account that earns simple interest at a rate of 4.5% per year

The formula for simple interest is given as:

$Simple\ Interest = \frac{p \times n \times r}{100}$

Where, "p" is the principal and "n" is the number of years and "r" is the rate of interest

From given,

p = 15000

r = 4.5 %

n = 6 years

Substituting the values we get,

$Simple\ Interest = \frac{15000 \times 4.5 \times 6}{100}\\\\Simple\ Interest = 150 \times 4.5 \times 6\\\\Simple\ Interest = 4050$

Thus simple interest earned over 6 years is $ 4050

6 0

4 years ago

A = 6x – 18° B = 14x + 38°

Luba_88 [7]

The measure of A is 30 degrees

explanation:
(6x-18)+(14x+38)=180
x=8

6(8)-18=30

5 0

3 years ago

Read 2 more answers