The z score is a score used to determine the number of standard deviations by which the raw score is above or below the mean, it is given by the equation:

$z=\frac{x-\mu}{\sigma} \\\\\mu=mean, \sigma=standard\ deviation,x=raw\ score\\\\for\ a\ sample\ n:\\\\z=\frac{x-\mu}{\sigma/\sqrt{n} }$

Given that μ = 650, σ = 50. To find the probability that 5 students who have a mean of 490, we use:

$z=\frac{x-\mu}{\sigma/\sqrt{n} } =\frac{490-650}{50/\sqrt{5} } =-7.16$

From the normal distribution table, P(x < 490) = P(Z < -7.16) = 0.0001 = 0.01%

Since only a small percentage of people score about 490, hence the local newspaper editor should write a scathing editorial about favoritism

4 0

2 years ago

Help me plzzzzzzzzzzzzzzzzzzz

lubasha [3.4K]

Answer:

Step-by-step explanation:

irdk sorry if its wrong :(

5 0

2 years ago

We randomize a sample for all the following reasons EXCEPT:

kirza4 [7]

Answer:

Step-by-step explanation:

6 0

2 years ago

2. David and Josh both drove to their grandmother's birthday party. David drove 225 miles and made it in 3 hours. Josh drove 320

AnnyKZ [126]

Answer:

Josh was driving faster

Step-by-step explanation:

Josh was going faster becuase 320 divided by 4 is 80

and 225 divided by 3 is 75.

In conclusion Josh was going faster by 5mph.

6 0

3 years ago

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