Linear equation- Please help☹️

Brian was scuba diving at the Great Barrier Reef in Australia. After he jumped in the water, he descended 18 feet. Then he rose

Levart [38]

amswer:

-13 feet

step by step:

-18+5=-13

8 0

2 years ago

i dont understand equations of parallel and perpendicular lines here's one of my teachers examples y=2x+4 (-2,1)

SIZIF [17.4K]

Parallel lines will never touch each other while perpendicular forms like an X shape. The slope for the parallel is the same while the perpendicular is a negative reciprocal. (Ex for negative reciprocal. 2/4=4/2)

8 0

2 years ago

A sample of 12 radon detectors of a certain type was selected, and each was exposed to 100 pCI/L of radon. The resulting reading

valkas [14]

Answer:

Null hypothesis: $\mu = 100$

Alternative hypothesis: $\mu \neq 100$

$t=\frac{98.375-100}{\frac{6.109}{\sqrt{12}}}=-0.921$

$p_v =2*P(t_{11}$

Step-by-step explanation:

1) Data given and notation

Data: 105.6, 90.9, 91.2, 96.9, 96.5, 91.3, 100.1, 105.0, 99.6, 107.7, 103.3, 92.4

We can calculate the sample mean and deviation for this data with the following formulas:

$\bar X =\frac{\sum_{i=1}^n X_i}{n}$

$s=\sqrt{\frac{\sum_{i=1}^n (X_i- \bar X)^2}{n-1}}$

The results obtained are:

$\bar X=98.375$ represent the sample mean

$s=0.6.109$ represent the sample standard deviation

$n=12$ sample size

$\mu_o =100$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

2) State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is equal to 100pCL/L, the system of hypothesis are :

Null hypothesis: $\mu = 100$

Alternative hypothesis: $\mu \neq 100$

Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

3) Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{98.375-100}{\frac{6.109}{\sqrt{12}}}=-0.921$

4) P-value

First we need to find the degrees of freedom for the statistic given by:

$df=n-1=12-1=11$

Since is a two sided test the p value would given by:

$p_v =2*P(t_{11}$

5) Conclusion

If we compare the p value and the significance level assumed $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the true mean is not significant different from 100 at 5% of significance.

3 0

3 years ago

Riley is saving up to buy a new television. She needs a total of $1,049.77. Riley has saved $200.79 already and earns $77.18 per

Xelga [282]

11 weeks are required for Riley to work to save enough money to buy the new television

<h3><u>Solution:</u></h3>

Given that Riley needs a total of $1,049.77

Riley has saved $200.79 already and earns $77.18 per week at her job

To find: Number of weeks Riley need to work to save enough money to buy the new television

Remaining amount needed = $1,049.77 - $200.79

Remaining amount needed = $ 848.98

Let "n" be the number of weeks Riley need to work to save enough money to buy the new television

Also she earns $77.18 per week at her job

1 week ⇒ $ 77.18

"n" weeks ⇒ $ 848.98

Therefore, by cross multiplication,

$n \times 77.18 = 1 \times 848.98\\\\n = \frac{848.98}{77.18}\\\\n = 11$

Therefore 11 weeks are required for her to work to save enough money to buy the new television

<h3><u>Method 2:</u></h3>

<em>Total amount = amount already saved + ($77.18 per week at her job)("n" weeks)</em>

1,049.77 = 200.79 + (77.18)(n)

1049.77 - 200.79 = 77.18n

848.98 = 77.18n

$n = \frac{848.98}{77.18}$

n = 11

Therefore 11 weeks are required for her to work to save enough money to buy the new television

5 0

3 years ago

Which is a list of all the zeros of x^5 + 7x^4 = 18x³?

Andrei [34K]

Answer:

B

Step-by-step explanation:

Because there is three numbers

3 0

2 years ago