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3 years ago

I need help on this

Mathematics

2 answers:

Schach [20]3 years ago

5 0

Answer:

Step-by-step explanation:

the numbers were not mentioned twice.

Kay [80]3 years ago

3 0

Answer:

no clue

Step-by-step explanation:

i have no clue

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Multiply.<br> 4v (3)<br> help?

dsp73

Answer:

12th ...

Step-by-step explanation:

4v (3)

=4v × 3 = 12v

6 0

3 years ago

A dealer sold a car to a man and made

fenix001 [56]

Answer:

<u></u>

Step-by-step explanation:

Selling at a loss of 5% means it was sold for 95% of its purchase value.

If 120.175 equals to 95% then 100%(the purchase value) is 126.500.

120.175/95*100 = 126.500 (plenty of other ways to calculate this, but this is one of the easiest)

So now we change to the dealer's perspective, he sold the car for 126.500 and for him that meant a 15% profit. If the purchase value is 100%, then the sale value is 115% (purchase value+15% profit)

Calculate the purchase value:

126.500/115*100 = 110.000

The dealer bought the car for 110.000, sold it for 126.500, so he made a profit of 16.500 (126.500-110.000) which is a 15% profit (15% of 110.000 is 16.500).

5 0

3 years ago

An educational psychologist wishes to know the mean number of words a third grader can read per minute.

Rama09 [41]

Answer: 208.

Step-by-step explanation:

The formula to find the minimum sample size is given by :-

$n= (\dfrac{z^*\times \sigma}{E})^2$ (1)

, where z* = critical z-value (two tailed).

$\sigma$ = Standard deviation ( from prior study ) and E = Margin of error.

As per given , we have

Margin of error : E= 0.29

Confidence level = 85%

Significance level = $\alpha=1-0.85=0.15$

Using z-table , the critical value (two -tailed)= $z^*=z_{\alpha/2}=z_{0.15/2}=z_{0.075}=1.439$

As per previous study , Variance = $\sigma^2=8.41$

$\sigma=\sqrt{8.41}=2.9$

Now, the required minimum sample size = $n= (\dfrac{(1.439)\times (2.9)}{0.29})^2$ [Substitute the values in formula (1)]

$n=(14.39)^2$

$n=207.0721\approx208$ [ Round to the next integer]

Hence, the minimum number of third graders that must be included in a sample = 208.

5 0

3 years ago

The attendant at a parking lot compared the number of hybrid vehicles to the total number of vehicles in the lot over a weekend.

EastWind [94]

We are given:

The ratios of the number of hybrid vehicles to the total number of vehicles in the lot over a weekend (3 days) are equivalent.

This means that if on day 1, 100 hybrid cars parked and there are 300 cars in total, the ratio is 1 is to 3.

Therefore, on day 2 and 3, we can determine the number of hybrid cars parked given the total number of cars parked using the ratio, and vice versa.

3 0

3 years ago

Two point particles are attached to each other via a light in-extensible string that passes over a ring hanging from the ceiling

arlik [135]

a. The expression for the tension in the string is T = mg

b. The expression for the tension in the chain is T = 2mg

To solve the problem, we need to know what tension is.

<h3>What is tension?</h3>

This is the opposing force in a stretched material.

<h3>a. Tension in the string</h3>

The expression for the tension in the string is T = mg

Since the string supports the weight of the object, the tension in the string equals the weight of the particle.

Let

T = tension in sring and
W = weight of particle = mg where
m = mass of particle and
g = acceleration due to gravity

So, T = W

T = mg

So, the expression for the tension in the string is T = mg

<h3>b. Tension in chain</h3>

The expression for the tension in the chain is T = 2mg

<h3 />

Since the chain supports both strings, the tension in the chain equals the tension in both strings.

Let

T' = tension in chain and
T = tension in each string

So, T' = T + T

T' = 2T

T' = 2W

T' = 2mg

So, the expression for the tension in the chain is T = 2mg

<h3 />

Learn more about tension here:

brainly.com/question/24994188

5 0

2 years ago

I need help on this ​

I need help on this