A florist wants to open her own retail store. She researches the prices charged at three local

Guess the number. The number has two digits. The sum of the digits is eight. If the digits are reversed, the result is 18 less t

kirill115 [55]

35 + 18 = 53
35 is you answer

8 0

3 years ago

The distribution of the number of viewers for the American Idol TV broadcasts follows the normal distribution of a mean of 29 mi

e-lub [12.9K]

Answer:

a) $P(30$

And we can find this probability on this way:

$P(0.2$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(0.2$

b) $P(X\geq 23)=P(\frac{X-\mu}{\sigma}\geq \frac{23-\mu}{\sigma})=P(Z\geq \frac{23-29}{5})=P(Z\geq -1.2)$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(Z\geq -1.2)=1-P(Z$

c) $P(X> 40)=P(\frac{X-\mu}{\sigma}> \frac{40-\mu}{\sigma})=P(Z\geq \frac{40-29}{5})=P(Z> 2.2)$

And in order to find the probabilitiy we can use tables for the normal standard distribution, excel or a calculator.

$P(Z>2.2)=1-P(Z$

Step-by-step explanation:

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) Part a

Let X the random variable that represent the number of viewers for the American Idol TV of a population, and for this case we know the distribution for X is given by:

$X \sim N(29,5)$