If $X$ is a random variable representing test scores, then the 41st percentile is the score $x$ such that $P(X\le x)=0.41$ . Transform $X$ to the random variable $Z$ that follows the standard normal distribution via $X=31.5+7.3Z$ :

$P(X\le x)=P\left(\dfrac{X-31.5}{7.3}\le\dfrac{x-31.5}{7.3}\right)=P\left(Z\le\dfrac{x-31.5}{7.3}\right)=0.41$

The $z$ -score for the 41st percentile is about -0.2275, so

$\dfrac{x-31.5}{7.3}\approx-0.2275\implies\boxed{x\approx29.8}$

6 0

4 years ago

PLEASE HELP!! ILL GIVE →BRAINLIEST!←

Tems11 [23]

Answer:

It will take him 50 minutes to complete the painting.

Step-by-step explanation:

6 0

3 years ago

What is the surface area of a cube with the side length of 18 m?

beks73 [17]

Answer: A=1944m²

Step-by-step explanation:

A=6a2=6·182=1944m² ← Work

* Hopefully this helps:) Mark me the brainliest:)!!

5 0

4 years ago

Factor completely : 100 z^2-16y^2

mojhsa [17]

4 (5z+2y) (5z-2y) (Ignore this)

8 0

4 years ago