Can you help me with these 4 problems?

Sam read 20% of the book on Monday and 0.2 of the book on Tuesday. If he read 50% of the remainder on Wednesday and still had 36

KonstantinChe [14]

Okay first you need to convert 0.2 to a percentage which would be 20% then 20% + 20% = 40% then it says he read 50%, 50% of 36 means that you have to multiply 36 two times to get, 72 then you do 72 * 40% = 28.8 = 29 + 72 = 101 pages in all then 101- 40%= 60.6 is how many pages were read on Monday and Tuesday.

8 0

3 years ago

For a given IQ test, an individual is considered a genius if their score falls more than three standard deviations from the mean

ki77a [65]

Answer:

$P(Z>3) = 1-P(Z$

So then the probability that an individual present and IQ higher than 3 deviation from the mean is 0.00135

And if we find the number of individuals that can be considered as genius we got: 0.00135*1500=2.025

And we can say that the answer is a.2

Step-by-step explanation:

1) Previous concepts

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".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

2) Solution to the problem

Let X the random variable that represent the IQ scores of a population, and for this case we know the distribution for X is given by:

$X \sim N(\mu=?,\sigma=?)$