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3 years ago

Mona wants to buy carpet for a floor in her house.

Mathematics

1 answer:

Musya8 [376]3 years ago

8 0

Answer:

13.05

Step-by-step explanation:

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Hat is the simplified form of 24r-3( 2r-5t)-4t?

m_a_m_a [10]

Answer:

18r + 11t

(Because there are 2 different variable, don't combine them together)

3 0

2 years ago

M and N are equilateral triangles. The scale factor of M to N is 8 : 4.1 and the area of triangle M is 320 square inche. find th

Lesechka [4]

Answer:

84.05 square inches

Step-by-step explanation:

Given;

Area of N = 320×(4.1/8)^2 = 84.05 square inches

7 0

3 years ago

Read 2 more answers

At noon, a tank contained 10 cm of water. after several hours, it contained 7 cm of water. what is the percent decrease of water

andrey2020 [161]

Amount of decreased water = 3/10

Then, it would be 3/10 * 100 = 30%

So, your answer is 30%

7 0

2 years ago

Here are summary statistics for randomly selected weights of newborn girls: nequals=174174, x overbarxequals=30.930.9 hg, seq

MaRussiya [10]

Answer:

The 95% confidence interval would be given by (29.780;32.020)

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".

$\bar X=30.9$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=7.5 represent the sample standard deviation

n=174 represent the sample size

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

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

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=174-1=173$

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 tabel to find the critical value. The excel command would be: "=-T.INV(0.025,173)".And we see that $t_{\alpha/2}=1.97$ , this value is similar to the obtained with the normal standard distribution since the sample size is large to approximate the t distribution with the normal distribution.