3 years ago

Please help 30 points :)

Mathematics

1 answer:

bearhunter [10]3 years ago

4 0

Hi,
hope that helps

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On Monday , 334 students went on a trip to the zoo . all 8 buses were filled and 6 students had to travel in cars . how many stu

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Answer:

41 students on each bus

Step-by-step explanation:

334 - 6 = 328/ 8 = 41

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3 years ago

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The lifetime of a certain brand of battery is known to have a standard deviation of 9 hours. Suppose that a random sample of 90

Rina8888 [55]

Answer:

lower limit : 36.44

upper limit : 39.56

Step-by-step explanation:

Given :

s = 9

n = 90

x = 38.9

Alpha, α = 0.10

∴ $z_{\alpha/2}=z_{0.05} = 1.645$

The confidence interval is :

$=x \pm\left(z_{\alpha /2} \times \frac{s}{\sqrt{n}}\right)$

$=38.9 \pm\left(1.645 \times \frac{9}{\sqrt{90}}\right)$

$=38.9 \pm 1.56$

$=(36.44, 39.56)$

Therefore,

lower limit : 36.44

upper limit : 39.56

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3 years ago

What is the solution to the system of equations? Use the substitution method. Y=?3x+12x+5y=18

rodikova [14]

The answer is

$y = - 3x + \frac{18}{5}$

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3 years ago

On a partly cloudy day, Derek decides to walk back from work. When it is sunny, he walks at a speed of s miles/hr (s is an integ

Setler [38]

Answer: $\frac{1}{7}$

Step-by-step explanation:

Given

sunny day speed= s mph

Rainy day speed=s+1 mph

Derek average speed =2.8 miles/hr

s<2.8<s+1

so on sunny day speed must be 2 mph

and on rainy day speed must be 3 mph

$v_{avg}=\frac{distance}{time\ taken}$

Let x be the distance traveled in sunny and y be the distance traveled in rainy weather

$2.8=\frac{x+y}{\frac}{x}{2}+\frac{y}{3}}$

Let $\frac{x}{y}=z$

$2.8=\frac{z+1}{\frac{z}{2}+\frac{1}{3}}$

$z=\frac{1}{6}$

Fraction of distance traveled on sunny weather

$\frac{x}{x+y}=\frac{z}{z+1}=\frac{1}{7}$

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3 years ago

Suppose that 30% of flies are black, and 70% are grey. Two flies are chosen at random, what is the probability that the chosen f

Neporo4naja [7]

Probability of choosing a black fly = 30/100 = 0.3

Probability of choosing a grey fly = 70/100 = 0.7

So, probability of choosing 2 grey flies = 0.7*0.7 = 0.49

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3 years ago