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Digiron [165]
3 years ago
5

Find the circumference of the circle, round to the nearest tenth 21 m Answer:

Mathematics
2 answers:
Lorico [155]3 years ago
6 0

Answer:

Circumference is 131.94

Step-by-step explanation:

Circumference Formula is C=2πr

Enter 21 for r so it will look like C=2(π)(21)

That makes it equal 131.9468915 so since you are rounding to the nearest tenth, you go next to the 4 and since it is a 6, it will round the 4 up to a 5

so that will make the answer 131.94

Hope this helps!

Liono4ka [1.6K]3 years ago
4 0

Answer:

yeetyeetyeetyeetyeetyeet

Step-by-step explanation:

You might be interested in
Each year about 1500 students take the introductory statistics course at a large university. This year scores on the nal exam ar
nikitadnepr [17]

Answer:

a) Left-skewed

b) We should expect most students to have scored above 70.

c) The scores are skewed, so we cannot calculate any probability for a single student.

d) 0.08% probability that the average score for a random sample of 40 students is above 75

e) If the sample size is cut in half, the standard error of the mean would increase fro 1.58 to 2.24.

Step-by-step explanation:

To solve this question, we need to understand skewness,the normal probability distribution and the central limit theorem.

Skewness:

To undertand skewness, it is important to understand the concept of the median.

The median separates the upper half from the lower half of a set. So 50% of the values in a data set lie at or below the median, and 50% lie at or above the median.

If the median is larger than the mean, the distribution is left-skewed.

If the mean is larger than the median, the distribution is right skewed.

Normal probabilty distribution:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central limit theorem:

The Central Limit Theorem estabilishes that, for a random variable X, with mean \mu and standard deviation \sigma, the sample means with size n of at least 30 can be approximated to a normal distribution with mean \mu and standard deviation, also called standard error of the mean s = \frac{\sigma}{\sqrt{n}}

(a) Is the distribution of scores on this nal exam symmetric, right skewed, or left skewed?

Mean = 70, median = 74. So the distribution is left-skewed.

(b) Would you expect most students to have scored above or below 70 points?

70 is below the median, which is 74.

50% score above the median, and 50% below. So 50% score above 74.

This means that we should expect most students to have scored above 70.

(c) Can we calculate the probability that a randomly chosen student scored above 75 using the normal distribution?

The scores are skewed, so we cannot calculate any probability for a single student.

(d) What is the probability that the average score for a random sample of 40 students is above 75?

Now we can apply the central limit theorem.

\mu = 70, \sigma = 10, n = 40, s = \frac{10}{\sqrt{40}} = 1.58

This probability is 1 subtracted by the pvalue of Z when X = 75. So

Z = \frac{X - \mu}{\sigma}

By the Central limit theorem

Z = \frac{X - \mu}{s}

Z = \frac{75 - 70}{1.58}

Z = 3.16

Z = 3.16 has a pvalue of 0.9992

1 - 0.9992 = 0.0008

0.08% probability that the average score for a random sample of 40 students is above 75

(e) How would cutting the sample size in half aect the standard error of the mean?

n = 40

s =  \frac{10}{\sqrt{40}} = 1.58

n = 20

s =  \frac{10}{\sqrt{20}} = 2.24

If the sample size is cut in half, the standard error of the mean would increase fro 1.58 to 2.24.

4 0
3 years ago
The ratio of two side lengths for the triangle is given. What is the value of “q” AB:BC is 3:4
Vera_Pavlovna [14]

Answer:

q=8.5

Step-by-step explanation:

The ratio of the side lengths (AB) and (BC) is given. One is also given an expression for the side lengths of each of these sides. Set up a proportion to describe this scenario, then solve using cross products;

\frac{AB}{BC}=\frac{3}{4}

Substitute,

\frac{60}{10q+15}=\frac{3}{4}

Cross products,

\frac{60}{10q+15}=\frac{3}{4}

(60)(4)=(10q+15)(3)\\\\240=30q+45

Inverse operations,

240=30q+45\\\\195=30q\\\\8.5=q

4 0
2 years ago
I need help i dont know the answers
Arlecino [84]

Answer: Change the number: 36

To:48

Step-by-step explanation:

12x2 is 24 but 24 x 2 isn’t 36

5 0
3 years ago
In a test of the effectiveness of garlic for lowering​ cholesterol, 8181 subjects were treated with raw garlic. Cholesterol leve
xz_007 [3.2K]

Answer:

With garlic​ treatment, the mean change in LDL cholesterol is not greater than 0.

Step-by-step explanation:

The dependent <em>t</em>-test (also known as the paired <em>t</em>-test or paired samples <em>t</em>-test) compares the two means associated groups to conclude if there is a statistically significant difference amid these two means.

In this case a paired <em>t</em>-test is used to determine the effectiveness of garlic for lowering​ cholesterol.

A random sample of 81 subjects were treated with raw garlic. Cholesterol levels were measured before and after the treatment.

The hypothesis for the test can be defined as follows:

<em>H₀</em>: With garlic​ treatment, the mean change in LDL cholesterol is not greater than 0, i.e. <em>d</em> ≤ 0.

<em>Hₐ</em>: With garlic​ treatment, the mean change in LDL cholesterol is greater than 0, i.e. <em>d</em> > 0.

The information provided is:

\bar d=0.40\\SD_{d}=16.2\\\alpha =0.01

Compute the test statistic value as follows:

t=\frac{\bar d}{SD_{d}/\sqrt{n}}\\\\=\frac{0.40}{16.2/\sqrt{81}}\\\\=0.22

The test statistic value is 0.22.

Decision rule:

If the <em>p</em>-value of the test is less than the significance level then the null hypothesis will be rejected and vice-versa.

Compute the <em>p</em>-value of the test as follows:

p-value=P(t_{n-1}>0.22)\\=P(t_{80}>0.22)\\=0.4132

*Use a <em>t</em>-table.

The <em>p</em>-value of the test is 0.4132.

<em>p-</em>value= 0.4132 > <em>α</em> = 0.01

The null hypothesis was failed to be rejected.

Thus, it can be concluded that with garlic​ treatment, the mean change in LDL cholesterol is not greater than 0.

3 0
3 years ago
Can u plzz help me with my homework
schepotkina [342]
The unit rate for Hakim's car is traveling 30 feet per second (I just simplified 600/20). Then the unit rate for Andre's motorcycle would be 25 feet per second (I simplified 300/12). So in conclusion, Hakim's car is traveling faster. So then, 30 > 25.
6 0
3 years ago
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