Desiree ran 12 miles in 1 hr, 48 minutes, What was Desiree's average running rate, in minutes per mile

Perfect Squaress less than 30

levacccp [35]

The perfect whole squares are 1, 4, 9, 16, 25, 36, 49, 64, 81, 100.

Less than 30 are:

5 0

3 years ago

A self proclaimed psychic was tested for ESP. The psychic was presented with 200 cards face down and asked to determine if the c

swat32

Answer:

The 95% confidence interval would be given (0.172;0.288).

We are confident at 95% that the true probability that the psychic correctly identifies the symbol on the card in a random trial is between (0.172;0.288).

We can conclude that her random guessing would have got her correct 20% of the time. Since the confidence interval contains 0.2, she has no psychic powers, rather she just guessed it like normal people. Any person could have got it correct this many times.

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".

Description in words of the parameter p

$p$ represent the probability that the psychic correctly identifies the symbol on the card in a random trial

$\hat p$ represent the estimated probability that the psychic correctly identifies the symbol on the card in a random trial

n=200 is the sample size required

$z_{\alpha/2}$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Numerical estimate for p

In order to estimate a proportion we use this formula:

$\hat p =\frac{X}{n}$ where X represent the cases successful

$\hat p=\frac{46}{200}=0.23$ represent the estimated probability that the psychic correctly identifies the symbol on the card in a random trial

Confidence interval

The confidence interval for a proportion is given by this formula:

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 95% confidence interval the value of $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.96$

And replacing into the confidence interval formula we got:

$0.23 - 1.96 \sqrt{\frac{0.23(1-0.23)}{200}}=0.172$

$0.23 + 1.96 \sqrt{\frac{0.23(1-0.23)}{200}}=0.288$

And the 95% confidence interval would be given (0.172;0.288).

We are confident at 95% that the true probability that the psychic correctly identifies the symbol on the card in a random trial is between (0.172;0.288).

We can conclude that her random guessing would have got her correct 20% of the time. Since the confidence interval contains 0.2, she has no psychic powers, rather she just guessed it like normal people. Any person could have got it correct this many times.

6 0

3 years ago

I WILL GIVE BRAINLY! The surface of a table to be built will be in the shape shown below. The distance from the center of the sh

ki77a [65]

Answer:

draw lines center to vertex
43.5 square inches
261 square inches

Step-by-step explanation:

<u>Part A</u>:

The area can be decomposed into triangles by drawing a line from the center to each vertex of the hexagon.

__

<u>Part B</u>:

The area of each triangle is given by the triangle area formula:

A = (1/2)bh

A = (1/2)(10 in)(8.7 in) = 43.5 in²

__

<u>Part C</u>:

The area of the table top is 6 times the area of one triangle:

surface area = 6(43.5 in²) = 261 in²

3 0

3 years ago

Read 2 more answers

Solve this equation 53y - 55 = 42y

stiv31 [10]

53y-42y=55
11y=55
Y=55/11 =5

6 0

3 years ago

Read 2 more answers

Which algebraic expression has a term with a coefficient of 3?

aleksandrvk [35]

Answer:

3x

Step-by-step explanation:

the value close to the alphabet is the coefficient

7 0

3 years ago