HELP ME ASAP WITH MATH MONEY & WAGES

Allushta [10]

Answer:

no le entiendo por qué estás en inglés

7 0

2 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

Rewrite the expression by combining like terms. 4x2 - 2x2 + 2y + 6y2 - y + x2

olasank [31]

Answer:

32 +6y^2+

Step-by-step explanation:

3 0

2 years ago

Find the slope for the following line: y=3/4x-7

Kitty [74]

The slope would be 3/4!

3 0

3 years ago

Read 2 more answers

A building contractor buys 60% of his cement from supplier A and 40% from supplier B. A total of 95% of the bags from A arriv

docker41 [41]

Answer: 0.665.

Step-by-step explanation:

60% of the bags are from supplier A, and 95% of them are undamaged.

40% of the bags are from supplier B, and 75% of them are undamaged.

Then, the number of undamaged bags from supplier A is:

0.6*0.95 = 0.57 or 57%

from B is:

0.4*0.75 = 0.3 or 30%

This means that the percentage of undamaged bags is:

57% + 30% = 87%.

Then, the probability that an undamaged bag is from supplier A is equal to the percentage of undamaged bags that came from supplier A (57%) and the total percentage of undamaged bags (87%) this is:

P = 57%/87% = 0.655 or 65.5%

Then the probability that an undamaged bag comes from supplier A is 0.665.

7 0

2 years ago