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3 years ago

6

A car travels a distance of 360 miles in 6 hours. What is the average speed of the car for this trip? Solve for speed.

1 answer:

Nastasia [14]3 years ago

6 0

Answer:

60 m/h

Step-by-step explanation:

S = d/t

S= 360/60

S= 60

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A random sample of 9 wheels of cheese yielded the following weights in pounds has a sample mean of 20.90 and a sample variance o

Ronch [10]

Answer:

$2.002 \leq \sigma^2 \leq 11.365$

Step-by-step explanation:

1) Data given and notation

s represent the sample standard deviation

$s^2$ represent the sample variance

n=9 the sample size

Confidence=90% or 0.90

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 mean or variance 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.

The Chi Square distribution is the distribution of the sum of squared standard normal deviates .

2) Calculating the confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

On this case we need to find the sample standard deviation with the following formula:

$s=sqrt{\frac{\sum_{i=1}^9 (x_i -\bar x)^2}{n-1}}
The sample variance given was [tex]s^2=3.45$

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=9-1=8$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical values.

The excel commands would be: "=CHISQ.INV(0.05,8)" "=CHISQ.INV(0.95,8)". so for this case the critical values are:

$\chi^2_{\alpha/2}=15.507$

$\chi^2_{1- \alpha/2}=2.732$

And replacing into the formula for the interval we got:

$\frac{(9)(3.45)}{15.507} \leq \sigma \frac{(9)(3.45)}{2.732}$

$2.002 \leq \sigma^2 \leq 11.365$

7 0

3 years ago

If 2X = 4096, find value of x.

Scorpion4ik [409]

Answer:

transpose 2 towards 4096

Step-by-step explanation:

2048 Answer

4 0

3 years ago

PLZ HELP ASAP!!!!! <img src="https://tex.z-dn.net/?f=" id="TexFormula1" title="" alt="" align="absmiddle" class="latex-formula">

AveGali [126]

The simplified expression of $$4 x \cdot \frac{1}{x^{-5}} \cdot x^{-3}$ is $4x^3$ .

Solution:

Given expression is $4 x \cdot \frac{1}{x^{-5}} \cdot x^{-3}$ .

To simplify the given expression.

$$\Rightarrow4 x \cdot \frac{1}{x^{-5}} \cdot x^{-3}$

Using exponent rule: $\frac{1}{a^{-m}}=a^m$

$$\Rightarrow4x \cdot x^{5}.x^{-3}$

Using another exponent rule: $a^m \cdot a^n=a^{m+n}$

$$\Rightarrow4x \cdot x^{5-3}$

$$\Rightarrow4x \cdot x^{2}$

Using exponent rule: $a^m \cdot a^n=a^{m+n}$

$$\Rightarrow4x^{1+2}$

$$\Rightarrow4x^3$

Hence the simplified expression of $$4 x \cdot \frac{1}{x^{-5}} \cdot x^{-3}$ is $4x^3$ .

8 0

3 years ago

Evaluate the expression 3(7 + 4)2 − 24 ÷ 6

solong [7]

Answer:

3(7 + 4)2 − 24 ÷ 6 = 62

Step-by-step explanation:

3(7 + 4)2 − 24 ÷ 6 is the given expression.

Now, by the rule of BODMAS, where B = Bracket, O= of, D = divide,

M = multiplication, A = addition and S = subtraction

we try and solve the following expression in the same order.

Solving the bracket first, we get

3<u>(7 + 4)</u>2 − 24 ÷ 6 = 3(<u>11</u>)2 − 24 ÷ 6 =<u> 66</u> − 24 ÷ 6

Next, we solve divide,

66 − <u>24 ÷ 6</u> = 66 - <u>4</u>

Next, solving the subtraction, 66 - 4 = 62

Hence, 3(7 + 4)2 − 24 ÷ 6 = 62

6 0

3 years ago

You select a marble from a jar. You know that

leva [86]

Answer:

5/7

Step-by-step explanation:

4 0

3 years ago