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3 years ago

15 points!!!

Mathematics

2 answers:

makvit [3.9K]3 years ago

4 0

0.4(3b +10) = 19

1.2b + 4 = 19

1.2b = 15

b = 15 / 1.2

b = 12.5

Bogdan [553]3 years ago

3 0

The value of b = 12.5.

In order to get this answer, we must:
First, simplify both sides of the equation.
0.4(3b + 10) = 19
(0.4)(3b) + (0.4)(10) = 19 (Distribute)
1.2b + 4 = 19
Next, we must subtract 4 from both sides.
1.2b + 4 - 4 = 19 - 4
1.2b = 15
Last, we must divide both sides by 1.2.
1.2b/1.2 = 15/1.2
Answer: b = 12.5

I hope this helps! :>

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Furkat [3]

Answer:

$z=\frac{0.438 -0.49}{\sqrt{\frac{0.49(1-0.49)}{338}}}=-1.912$

The p value for this case would be given by:

$p_v =2*P(z$

For this case the p value is higher than the significance level so then we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true proportion is not significantly different from 0.49 or 49%

Step-by-step explanation:

Information given

n=338 represent the random sample taken

X=148 represent the homes in Oregon were heated by natural gas

$\hat p=\frac{148}{338}=0.438$ estimated proportion of homes in Oregon were heated by natural gas

$p_o=0.49$ is the value that we want to test

represent the significance level

z would represent the statistic

$p_v$ represent the p value

Hypothesis to test

We want to check if the true proportion of interest is 0.49, then the system of hypothesis are.:

Null hypothesis: $p=0.49$

Alternative hypothesis: $p \neq 0.49$

The statitic is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

Replacing we got:

$z=\frac{0.438 -0.49}{\sqrt{\frac{0.49(1-0.49)}{338}}}=-1.912$

The p value for this case would be given by:

$p_v =2*P(z$

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4 years ago

Jack ran at 880 ft./min. For the first 10 min. Of the 3 mi. Race before slowing his pace to finish the race with a total time of

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Answer:

Jack ran 704 ft/min during the second half of the race.

Step-by-step explanation:

Here the distance traveled was 3 miles, and the total elapsed time was 20 minutes. Recall that distance = rate * time, or rate = distance / time.

Find the pace (speed, rate) for the second part of the race.

Here, the total distance was 3 miles and the elapsed time 20 minutes. Jack's average speed was thus 3/20 miles/minute. Converting this to feet per minute, we get:

3 mi 5280 ft

------------ * ------------- = 792 ft/min (Jack's average speed)

20 min 1 mi

Recall that the formula for finding the average of x and y is (x + y) / 2.

(1/2)(880 ft/min + p) = 792 ft/min; find p, which represents Jack's pace for the second part of the race.

If (1/2)(880 ft/min + p) = 792 ft/min, and we mult. both sides by 2, we get:

880 ft/min + p = 1584 ft/min.

To solve this for p, subtract 880 ft/min from both sides, obtaining:

p = 704 ft/min

Jack ran 704 ft/min during the second half of the race.

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Answer: Hello your question is incomplete below is the missing part of the question

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Step-by-step explanation:

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