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3 years ago

11

Sweet t noticed the ratio of long boards to short boards was 1:4. If there were 35 surfboards at the beach, how many were short

boards? Guys thanks for answering my questions!! :) :p

2 answers:

olya-2409 [2.1K]3 years ago

8 0

I believe the answer is 28 short boards

Digiron [165]3 years ago

4 0

Long/short = 1/4
short = ...
L/s = 1/4
L+s = 35
(L+s)/(1+4) = 35/5 = 7
L/1 = 7 --> L = 7
s/4 = 7 --> s = 28 (28 shorts)

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A jar contains a mixture of 10 black paperclips, 8 red paperclips, and 2 white paperclips all the same size. Determine the proba

Marizza181 [45]

There are 20 paper clips in total so

Black probability: 10/20 (50%)

Red probability: 8/20 (40%)

White probability: 2/20 (10%)

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4 years ago

On a coordinate plane, a curved line with a minimum value of (5.1, negative 7) and a maximum value of (0, 25), crosses the x-axi

liubo4ka [24]

Answer:

<u>The true statement is D</u>

Step-by-step explanation:

The rest of the question is the attached figure and the statement options.

A. Over the interval [–4, –2], the local minimum is 0.
B. Over the interval [–2, –1], the local minimum is 25.
C. Over the interval [–1, 4], the local minimum is 0.
D. Over the interval [4, 7], the local minimum is -7.

============================================================

According to the graph, we will check the options:

A. Over the interval [–4, –2], the local minimum is 0. (<u>Wrong</u>)

Because the minimum is -12

B. Over the interval [–2, –1], the local minimum is 25. (<u>Wrong</u>)

Because the minimum is 18

C. Over the interval [–1, 4], the local minimum is 0. (<u>Wrong</u>)

Because the minimum is at x = 4 less than zero

D. Over the interval [4, 7], the local minimum is -7. (<u>True</u>)

5 0

3 years ago

Read 2 more answers

If it takes Ashley 3 seconds to run from the batters box to first base at an average speed of 6.5 m/sec, what is the distance th

Zanzabum

I'm pretty sure you would do 6.5 times 3 and that would give you 19.5

5 0

3 years ago

A magazine conducts an annual survey in which readers rate their favorite cruise ship. All ships are rated on a 100-point scale,

Lyrx [107]

Answer:

a) The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =85.82-81.90=3.92$

b) $SE=\sqrt{(\frac{4.55^2}{35}+\frac{3.97^2}{44})}=0.975$

And the Margin of error is given by:

$Me= z_{\alpha/2} * SE=1.96*0.975=1.910$

c) The 95% confidence interval would be given by $2.009 \leq \mu_1 -\mu_2 \leq 5.83$ .

Step-by-step explanation:

Notation and previous concepts

$n_1 =35$ represent the sample of ships that carry fewer than 500 passengers

$n_2 =44$ represent the sample of ships that carry 500 or more passengers

$\bar x_1 =85.82$ represent the mean sample of of ships that carry fewer than 500 passengers

$\bar x_2 =81.90$ represent the mean sample of of ships that carry 500 or more passengers

$\sigma_1 =4.55$ represent the population deviation of ships that carry fewer than 500 passengers

$\sigma_2 =3.97$ represent the sample deviation of ships that carry 500 or more passengers

$\alpha=0.05$ represent the significance level

Confidence =95% or 0.95

The confidence interval for the difference of means is given by the following formula:

$(\bar X_1 -\bar X_2) \pm z_{\alpha/2}\sqrt{(\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2})}$ (1)

Part a

The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =85.82-81.90=3.92$

Part b: At 95% confidence, what is the margin of error?

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that $z_{\alpha/2}=1.96$

The standard error is given by the following formula:

$SE=\sqrt{(\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2})}$

And replacing we have:

$SE=\sqrt{(\frac{4.55^2}{35}+\frac{3.97^2}{44})}=0.975$

And the Margin of error is given by:

$Me= z_{\alpha/2} * SE=1.96*0.975=1.910$

Part c: What is a 95% confidence interval estimate of the difference between the population mean ratings for the two sizes of ships?

Confidence interval

Now we have everything in order to replace into formula (1):

$3.92-1.96\sqrt{(\frac{4.55^2}{35}+\frac{3.97^2}{44})}=2.009$

$3.92+1.96\sqrt{(\frac{4.55^2}{35}+\frac{3.97^2}{44})}=5.830$

So on this case the 95% confidence interval would be given by $2.009 \leq \mu_1 -\mu_2 \leq 5.83$ .

7 0

3 years ago

Can u guys answer my question 13 and 14 pls

Alika [10]

Answer:

√2=1.414

then :√8 +2√32 +3√128+4√50

√8=√2³ =2√2

2√32=√2^5 = 4*2√2 = 8√2

3√128 = 3√2^6*2=8*3√2 =24√2

4√50 =4√5²*2= 20√2

add results : 2√2+8√2 +24√2+20√2=54√2

<h2>54√2=54×1.414=76.356 ( it is not in the options)</h2>

x=7-4√3

√x+ 1/√x

√(7-4√3) +1/√(7-4√3) =

(8-4√3)/√(7-4√3)

(8-6.93)/√(7-6.93) = 4 ( after rounded to the nearest whole number)

4 is your answer

3 0

3 years ago