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2 years ago

Can somebody help me with these questions?

Mathematics

1 answer:

jarptica [38.1K]2 years ago

5 0

Answer:

5. (3)

6. (1)

Step-by-step explanation:

You might be interested in

If 1/8(8x+15)24, what is the value of x?

Lelechka [254]

Answer:

$x=22.125$ or $x=\frac{177}{8}$

Step-by-step explanation:

<u><em>The correct equation is</em></u>

$1/8(8x+15)=24$

solve for x

Multiply by 8 both sides to remove the fraction

$(8x+15)=192$

subtract 15 both sides

$8x=192-15\\8x=177$

divide by 8 both sides

$x=\frac{177}{8}$

$x=22.125$

3 0

3 years ago

An engineer is going to redesign an ejection seat for an airplane. The seat was designed for pilots weighing between 130 lb and

egoroff_w [7]

Answer:

a) $P(140$

$P(0.036$

b) $P(140< \bar X$

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".

Part a

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

$X \sim N(139,28.1)$

Where $\mu=139$ and $\sigma=28.1$

We are interested on this probability

$P(140$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(140$

And we can find this probability like this:

$P(0.036$

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

$P(0.036$

Part b

For this case we select a sample size of n =32. Since the distribution for X is normal then the distribution for the sample mean $\bar X$ is given by: