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3 years ago

Can someone please help me with this?

Mathematics

2 answers:

marishachu [46]3 years ago

7 0

V=12, comment if u need an explanation

elena-s [515]3 years ago

7 0

V=12 and just know like that.. i cant explain okey

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I need help please. I need the the discount and selling price. Thank you

Sati [7]

The discount is $1,880 and the selling price is $21,620, make sure to put the dollar sign to make sure you know what the number means

7 0

2 years ago

A Statistics professor has observed that for several years students score an average of 106 points out of 150 on the semester ex

tekilochka [14]

Answer:

Step-by-step explanation:

We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

µ = 106

For the alternative hypothesis,

µ > 106

It is a right tailed test because of >.

Since no population standard deviation is given, the distribution is a student's t.

Since n = 241,

Degrees of freedom, df = n - 1 = 241 - 1 = 240

t = (x - µ)/(s/√n)

Where

x = sample mean = 109

µ = population mean = 106

s = samples standard deviation = 8.3

a) test statistic, t = (109 - 106)/(8.3/√241) = 5.61

We would determine the p value using the t test calculator. It becomes

p = 0.00001

Since alpha, 0.05 > than the p value, 0.00001, then we would reject the null hypothesis. Therefore, At a 5% level of significance, this improvement seem to be practicallysignificant.

b) Confidence interval is written in the form,

(Sample mean - margin of error, sample mean + margin of error)

The sample mean, x is the point estimate for the population mean.

Margin of error = z × s/√n

Where

s = sample standard deviation

n = number of samples

From the information given, the population standard deviation is unknown, hence, we would use the t distribution to find the z score

df = 240

Since confidence level = 95% = 0.95, α = 1 - CL = 1 – 0.95 = 0.05

α/2 = 0.05/2 = 0.025

the area to the right of z0.025 is 0.025 and the area to the left of z0.025 is 1 - 0.025 = 0.975

Looking at the t distribution table,

z = 1.6512

Margin of error = 1.6512 × 8.3/√241

= 0.88

Confidence interval = 109 ± 0.88

7 0

3 years ago

In a horse race with 5 horses, you make a bet by predicting the ranking of all 5 horses. Suppose you place your bet at random. W

lapo4ka [179]

Answer:

P( top two horses are predicted incorrectly in incorrect order)

= $\frac{1}{2}$

Step-by-step explanation:

In the horse race the outcome can be predicted in 5! = 120 ways.

Now suppose the top two horses were predicted incorrectly in incorrect order. Now, the top horse can be predicted incorrectly in 4 ways.

Suppose the top horse was predicted to be in k-th position where k = 2, 3 ,4,5

so the second horse can be predicted to be in place from 1 to (k - 1)

So, the top two horses can be predicted incorrectly in incorrect order

in $\sum_{k =2}^{5}(k - 1)$ = 10 ways

and for each prediction of the two the remaining horses may be predicted in 3! = 6 ways.

Hence ,

P( top two horses are predicted incorrectly in incorrect order)

= $\frac{6 \times 10}{120}$

= $\frac{1}{2}$

8 0

2 years ago

I need help with number 46.

grigory [225]

Answer:

1:3

Step-by-step explanation:

1/3:1

We want the ratio with whole numbers

Multiply each side by 3

1/3*3 : 1*3

1:3

6 0

3 years ago

Answers with links will be reported

Ber [7]

Answer:

11 months

Step-by-step explanation:

the math that i did was i kept adding 400 to 2500 and counted every four hundred that i added witch was 11 until i got to 7000 so the answer is 11 months. You will have some left over which you will have 300 left over.

8 0

2 years ago