How many people said their favorite color is either blue or red? your answer should be in a number not percentage.

Using the same survey methodology: random sample of US residents between the ages of 18 to 75 who registered on the Crest websit

kirza4 [7]

Answer:

Stratified sampling

Step-by-step explanation:

Samples may be classified as:

Convenient: Sample drawn from a conveniently available pool.

Random: Basically, put all the options into a hat and drawn some of them.

Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.

Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.

Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.

In this question:

Population divided into groups, and random samples are drawn from the groups. This is a mark of stratified sampling.

6 0

3 years ago

The lengths of pregnancies are normally distributed with a mean of 269269 days and a standard deviation of 1515 days. a. Find th

kati45 [8]

Answer:

a. 0.38%

b. 266.75 days

Step-by-step explanation:

We have the following data, mean (m) 269 and standard deviation (sd) 15, therefore:

a. The first thing is to calculate the number z:

z (x) = (x - m) / sd

z (309) = (309-269) / 15 = 2.67

When looking in the normal distribution table (attached), we have that at this value of z, the probability is:

P (z> 2.67), that is to say we must look in the table -2.67 and this value corresponds to 0.0038, that is to say 0.38%

b. Find the z-value with a left tail of 44%, i.e. 0.44. We look in the table for this value and what value of z corresponds.

invNorm (0.44) = -0.15

Find the corresponding number of days:

x = z * sd + m

we replace

d = -0.15 * 15 + 269 = 266.75 days

7 0

3 years ago

What is y=-4/3x +6. y=2

Mekhanik [1.2K]

The given equation is:
[/tex]y=-\frac{4}{3}x+6 [/tex] and we need to evaluate this for y=2.
So, first step is to plug in 2 for y in the above equation. Therefore,

$2=-\frac{4}{3} x+6$
$2*3=-\frac{4}{3} x*3+6*3$ Multiply each sides by common denominator 3
$6=-4x+18$
6-18= -4x Subtract 18 from each sides.
-12=-4x
$-\frac{12}{-4} =-\frac{4x}{-4}$
So, x=3