Please help me I stink at math need all

13, what is the probability that the coin lands on heads the first two times and lands on tales third

lozanna [386]

Answer: The probability is 1/8

Explanation:

Probability is a ratio of the number of relevant outcomes and total number of possible outcomes.

We are flipping the coin three times.

The number of relevant outcomes is 1 (one triple {Head, Head, Tail})

The number of all possible outcomes is the product of 2 possibilities (Head or Tail) on first toss, times another 2 on second, times another 2 on third, so 2^3 = 8.

The probability P = 1/8

4 0

3 years ago

Write 6×10 to the power of 4 in standard form!<br> Please include an explanation!<br> Thanks!

lidiya [134]

Answer:

60,000

Step-by-step explanation:

Evalute

6 x 10*4

6 x 10,000

60,000 is the standard form :)

3 0

2 years ago

Read 2 more answers

In a sample of 53 walking canes, the average length was found to be 34.3in. with a variance of 1.9. Give a point estimate for th

Anna11 [10]

Answer:

1.38

Step-by-step explanation:

The point estimate for the population standard deviation of the length of the walking canes is given as the squareroot of variance. Since variance is provided as 1.9 then the standard deviation will be

$\sqrt 1.9=1.37840487520902\approx 1.38$

Therefore, rounded off to two decimal places, the standard deviation is approximately 1.38

6 0

2 years ago

Consider the probability that greater than 96 out of 153 DVDs will work correctly. Assume the probability that a given DVD will

ICE Princess25 [194]

Answer:

0.3594 = 35.94% probability that greater than 96 out of 153 DVDs will work correctly.

Step-by-step explanation:

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be 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.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$n = 153, p = 0.62$

So

$\mu = E(X) = np = 153*0.62 = 94.86$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{153*0.62*0.38} = 6$

Probability that greater than 96 out of 153 DVDs will work correctly.

97 or more DVDs, which is 1 subtracted by the pvalue of Z when X = 97. So

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

$Z = \frac{97 - 94.86}{6}$

$Z = 0.36$

$Z = 0.36$ has a pvalue of 0.6406

1 - 0.6406 = 0.3594

0.3594 = 35.94% probability that greater than 96 out of 153 DVDs will work correctly.

3 0

3 years ago

A snail can move 1/30 miles in 1/3 hour. How fast does a snail move in miles /hours

bekas [8.4K]

Answer: 1/10 miles/hour

To find how fast a snail moves in miles per hour, we can find the unit rate using a proportion.

The unit rate is the amount per one unit. In this problem, the unit is for one hour. One way to find the unit rate is by using a proportion.

<h2>Proportions</h2>

Proportions look like two fractions set equal to each other with a missing variable to solve.

<h3>State our variables</h3>

let <em>x</em> be the number of miles per hour

<h3>Write a proportion</h3>

The first fraction has a number for the numerator (top) and denominator (bottom), because the question gives us the information. The second fraction has a missing value, <em>x</em>, that we are solving for. We can write <em>x</em> in the numerator.

$\displaystyle{\frac{\frac{1}{30}\ mi}{\frac{1}{3}\ hr} = \frac{x\ mi}{1\ hr}}$

<h2>Solve</h2>

We can solve by finding the scale factor. The scale factor is the number we can multiply the numerator by to find <em>x</em>.

<h3>Find the scale factor</h3>

Start with the proportion.

$\displaystyle{\frac{\frac{1}{30}\ mi}{\frac{1}{3}\ hr} = \frac{x\ mi}{1\ hr}}$

To find the scale factor,

Take the denominator from the fraction with a variable: $1\ hr$
Take the denominator from the fraction that has no variable: $\frac{1}{3}\ hr$
Divide step 1 by step 2 and solve: $1\ hr\ \div\ \frac{1}{3}\ hr = 3$

Our scale factor is <u>3</u>.

<h3>Solve for x</h3>

We can find <em>x</em> by multiplying the numerator in the first fraction by the scale factor. This is because <em>x</em> is also in the numerator.

$\displaystyle{\frac{\frac{1}{30}\ mi}{\frac{1}{3}\ hr} = \frac{(\frac{1}{30}\ mi)*3}{1\ hr}}$

$\displaystyle{\frac{\frac{1}{30}\ mi}{\frac{1}{3}\ hr} = \frac{\frac{3}{30}\ mi}{1\ hr}}$

Simplify 3/30 by dividing the fraction by 3.

$\displaystyle{\frac{\frac{1}{30}\ mi}{\frac{1}{3}\ hr} = \frac{\frac{1}{10}\ mi}{1\ hr}}$

x = 1/10

∴ a snail moves 1/10 miles per hour.

Learn another way to solve proportions here: brainly.com/question/18437927

7 0

1 year ago