Suppose a large population has a mean μand standard deviation σ, and a simple randomsample of size nis taken. the sampling distribution of the sample mean xhas mean andvariance respectively equal to(a)μ/nand σ2/n.(b)μand σ/n.(c)μ/nand σ2/n2.(d)μand σ2/n.

(d) μ and σ²/n

Step-by-step explanation:

In a sampling distribution of sample means, the mean is equal to the population mean, which is μ.

The standard deviation of the sampling distribution of sample means is given by

σ/√n.

The variance of a distribution is the square of the standard deviation; this means the variance of the sampling distribution of sample means would be

(σ/√n)² = σ²/(√n)² = σ²/n

were is the equation

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.