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3 years ago

7th grade math help me please :)

Mathematics

2 answers:

Aneli [31]3 years ago

8 0

105 pounds ...............

katovenus [111]3 years ago

6 0

Answer:

105 pounds

Step-by-step explanation:

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A random number generator is used to select an integer from 1 to 100 (inclusively). What is the probability of selecting the in

natima [27]

Answer:

The correct answer is zero.

Step-by-step explanation:

A random variable generator selects an integer from 1 to 100 both inclusive leaves us with total number of possible sample as 101.

We need to find the probability of selecting the integer 194.

The probability of selecting 194 from the sample is zero as the point does not exist in the random variable generator. Thus we can never pick 194 from the random variable generator giving us the probability a zero.

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2 years ago

(8^2)^4 I'm struggling in my math and need help please

Serjik [45]

I think that equals 16777216

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3 years ago

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If there are 13 girls in the class and 7 boys what percent of the students are girls???

Mumz [18]

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2 years ago

4kg of cheese costs £10.80 how much would 3kg cost

lana66690 [7]

Answer:

£8.10

Step-by-step explanation:

Divide £10.80 by 4 to find the cost of 1 Kg, then multiply this by 3

£10.80 ÷ 4 = £2.70 ← cost of 1 Kg , then

cost of 3 Kg = 3 × £2.70 = £8.10

7 0

3 years ago

Read 2 more answers

Sulfur compounds cause "off-odors" in wine, so winemakers want to know the odor threshold, the lowest concentration of a compoun

sladkih [1.3K]

Answer:

a) If we construct a stemplot for the data we have this:

Stem Leaf

1 | 9

2 | 2 3 9

3 | 0 0 1 3 5

4 | 2

Notation: 1|9 means 19

b) $29.4-2.26\frac{6.75}{\sqrt{10}}=24.58$

$29.4-2.26\frac{6.75}{\sqrt{10}}=34.22$

So on this case the 95% confidence interval would be given by (24.58;34.22)

Step-by-step explanation:

For this case we have the following data:

30 30 42 35 22 33 31 29 19 23

Part a

If we construct a stemplot for the data we have this:

Stem Leaf

1 | 9

2 | 2 3 9

3 | 0 0 1 3 5

4 | 2

Notation: 1|9 means 19

As we can see the distribution is a little assymetrical to the right since we have not to much values on the right tail. But we can approximate roughly the distribution symmetric and with no outliers.

Part b

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".

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

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n 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 mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=29.4$

The sample deviation calculated $s=6.75$

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

$df=n-1=10-1=9$

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(0.025,9)".And we see that $t_{\alpha/2}=2.26$

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

$29.4-2.26\frac{6.75}{\sqrt{10}}=24.58$

$29.4-2.26\frac{6.75}{\sqrt{10}}=34.22$

So on this case the 95% confidence interval would be given by (24.58;34.22)

8 0

3 years ago