If µ = 400 and s = 100 the probability of selecting at random a score less than or equal to 370 equals ____.

1 answer:

3 0

You'll need to calculate the applicable z-score:
(given value of x) - (mean value)
z = -----------------------------------------------
standard deviation

370-400 -30
Here, z = --------------- = ---------- = -0.3
100 100

Use either a table of z scores or your calculator to determine the area under the standard normal curve to the left of z = -0.3.

According to my TI-83 Plus calculator, this area is 0.382.

The probability of selecting at random a score less than or equal to 370 is 0.382.

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lesantik [10]

Answer: x is -2

Steps:

- 1.2x + 2.5 = 0.8x + 6.5

- 1.2x - 0.8x = 6.5 - 2.5

- 2x = 4

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x = - 2

Brainliest pls if I am correct!