A study conducted in year 2002 found that the mean number of children under 18 per household in a certain community was 1.7. A statistician is trying to determine whether this number has changed in the last 6 years. She declares the null and alternative hypotheses to be: Null: The mean number of children per household in 2002 is equal to 1.7; Alternative: The mean number of children per household in 2002 is not equal to 1.7. Which of the following statements is true about this test? a. This is a step-tailed test.
b. This is a left-tailed test.
c. This is a two-tailed test.
d. This is a right-tailed test.

Asmall (but heavy) particle placed in a glass of water will follow a zigzag motion because the particle will bounce off of the water molecules it meets. this is called brownian motion. a physicist simulates this on a computer, by varying the distance a particle can travel (called the mean free length), on average, before it collides with a water molecule and assigning the change in motion to be one of 8 directions, each with a similar probability. by running the simulated particle (with the same mean free length) many times she determines that it should take 15 seconds, on average, for the particle to fall to the bottom, with a standard deviation of 1.5 seconds. next she lets a real particle fall through a glass of water and finds that it took 18 seconds. what does she conclude, and why?

The vertices of a triangle are a(7,5), b(4,2), c(9,2). what is m

In the triangles, bc =de and ac fe. if the mzc is greater than the mze, then ab isdfelth