What does v9 equal???????

6. Kathleen needs 240 valid signatures on a petition to get a crosswalk installed on her street. She knows

fredd [130]

Kathleen must get 300 signatures to make sure she will have enough valid signatures for the crosswalk

<em><u>Solution:</u></em>

Given that Kathleen needs 240 valid signatures on a petition to get a crosswalk installed on her street

She knows that about 20% of the signatures will not be valid for a variety of reasons

Let "x" be the number of signatures

invalid signature = 20 % of x

valid signatures = 240

Then, according to question,

total number of signatures - invalid signatures = 240

x - 20 % of x = 240

$x - 20 \% \times x = 240\\\\x - \frac{20}{100} \times x = 240\\\\x - 0.2x = 240\\\\0.8x = 240\\\\x = 300$

Therefore, she must get 300 signatures so that she will have enough valid signatures for the crosswalk

3 0

2 years ago

Five friends bake ginger bread and subsequently meet up for a tasting session. Each one gives one of his ginger

GenaCL600 [577]

Answer:

The five friends had 10 fingers to start with; one had two each

Step-by-step explanation:

The statement says each gave one of not all of his ginger in the toasting session.

4 0

2 years ago

A car tire with a radius of 16inches is turning at a rate of 120 revolutions per minute. Find the exact linear speed of the tire

anygoal [31]

Answer:

The speed of the tyre of the car is 1002.24 feet per minute .

Step-by-step explanation:

Given as :

The radius of the car wheel = r = 16 inches

Since 12 inches = 1 feet

So, 16 inches = $\frac{1}{12}$ ×16 = 1.33 feet

The number of revolution of the wheel = 120 revolution per minute

Let The speed of the wheel = s feet per minute

The circumference of wheel = 2 × $\pi$ × radius

where $\pi$ = 3.14

or, circumference = 2 × 3.14 × 1.33

Or, Circumference = 8.352 feet

Now , Speed = circumference of wheel × number of revolution

or, Speed = 8.352 feet × 120 revolution per minute

∴ Speed = 1002.24 feet per minute

Hence The speed of the tyre of the car is 1002.24 feet per minute . Answer

4 0

2 years ago

How much money do winners go home with from the television quiz show Jeopardy? To determine an answer, a random sample of winner

Liula [17]

Answer:

The 95% confidence interval would be given by (14444.04;33657.30)

Step-by-step explanation:

Previous concepts

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".

Data: $26,650 $6,060 $52,820 $8,490 $13,660$25,840 $49,840 $23,790 $51,480 $18,960$990 $11,450 $41,810 $21,060 $7,860

We can calculate the mean and the deviation from these data with the following formulas:

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

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

$\bar X=24050.67$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=17386.13 represent the sample standard deviation

n=15 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:

$df=n-1=15-1=14$

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(0.025,14)".And we see that $t_{\alpha/2}=2.14$