Ask question

Ask question

All categories

2 years ago

7

a fish tank is 50 centimeters long, 30 centimeters wide, and 40 centimeters high. It contains water up to a height of 28 centime

ters. How many more cubic centimeters of water are needed to fill the tank to a height of 35 centimeters.

1 answer:

Nitella [24]2 years ago

6 0

I think its 7 because 28+7=35

You might be interested in

Gina was earning $10 per hour. Then she received a 10% pay rate increase. Next month, her pay rate will decrease by 10%. What wi

forsale [732]

Answer:

$9.90 per hour

Step-by-step explanation:

This month:

Initial pay: $10 per hour

% raise : 10%

Dollar amount of raise = 10% x $10

= 10/100 x 10 = $1

Gina's pay after the raise = $10 + $1 = $11 per hour

Next Month:

Starting pay: $11 per hour

% decrease : 10%

Dollar amount of decrease = 10% x $11

= 10/100 x 11 = $1.10

Gina's pay after decrease = $11 - 1.10 = $9.90 per hour

8 0

2 years ago

Suppose that the researchers wanted to estimate the mean reaction time to within 6 msec with 95% confidence. Using the sample st

Lisa [10]

Answer:

a) The 95% confidence interval would be given by (509.592;550.308)

b) n=523 rounded up to the nearest integer

Step-by-step explanation:

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=530$ represent the sample mean for the sample

$\mu$ population mean

s=70 represent the sample standard deviation

n=48 represent the sample size (variable of interest)

Confidence =95% or 0.995

Part a

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The degrees of freedom are df=n-1=48-1=47

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: "=-T.INV(0.025,47)".And we see that $z_{\alpha/2}=2.01$

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

$530-2.01\frac{70}{\sqrt{48}}=509.692$

$530+2.01\frac{70}{\sqrt{48}}=550.308$

So on this case the 95% confidence interval would be given by (509.592;550.308)

Part b

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

Assuming that $\hat \sigma =s$

And on this case we have that ME =6msec, and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 95% of confidence interval is provided, $z_{\alpha/2}=1.96$ , replacing into formula (b) we got:

$n=(\frac{1.96(70)}{6})^2 =522.88 \approx 523$

So the answer for this case would be n=523 rounded up to the nearest integer

3 0

2 years ago

All of the following are ways to write 25 percent of N Except. A. (0.25)N B. 25/100N C. 1/4 N D. 25N

anygoal [31]

Except (D)
because it's 25N not 0.25N

6 0

2 years ago

All students are classified as either full-time or part-time. Kenneth conducted a survey in which he collected data on the perce

Crank

Answer:

A

Step-by-step explanation:

8 0

2 years ago

Suppose the average price for new cars in 2012 has a mean of $30,100 and a standard deviation of $5,600. Based on this informati

KatRina [158]

Answer:

($13,300,$46,900)

Step-by-step explanation:

We are given the following in he question:

Mean, μ = $30,100

Standard Deviation, σ = $5,600

Chebyshev's Theorem:

According to theorem atleast $1 - \dfrac{1}{k^2}$ percent of data lies within 2 standard deviations of mean.
For k = 3,

$1 -\dfrac{1}{(3)^2} = 0.889 \approx 89\%$

Thus, 89% of data lies within three standard deviation of mean.

$\mu - 3(\sigma) = 30100 - 3(5600) = 13300\\\mu + 3(\sigma) = 30100 + 3(5600) = 46900$

Thus, we expect at least 89% of new car prices to fall within ($13,300,$46,900)

3 0

2 years ago