Answer:
14
Step-by-step explanation:
The perimeter is the sum of the sides, so we have
2x+x+15+4x-7=57
= 7x+8
Subtracting 8 from both sides, we get
7x= 49
Dividing 7 from both sides, we get
x=7
Our sides are then 2x=14, x+15=22, and 4x-7=21. 14 is our answer
Answer:
52
Step-by-step explanation:
if it were five and over it would be 53, it's four though, so it would be 52.
Motorcycle shop maintains
U - used bikes
N - new bikes = 4N
1 U = 4N
? U = 16 new bikes
16/4 = 4. There are 4 used bikes that are in stock.
Answer:

Step-by-step explanation:
We have the right triangle and the trapezoid.
The formula of an area of a right triangle:

a, b - legs
We have the length of the legs 12in and 13.42 in. Substitute:

The formula of an area of a trapezoid:

b₁, b₂ - bases
h - height
We have the length of the bases 18in and 11.75in and the length of the height 6.12in. Substitute:

The area of the figure:

Substitute:

Answer:
a. The sample has more than 30 grade-point averages.
Step-by-step explanation:
Given that a researcher collects a simple random sample of grade-point averages of statistics students, and she calculates the mean of this sample
We are asked to find the conditions under which that sample mean can be treated as a value from a population having a normal distribution
Recall central limit theorem here
The central limit theorem states that the mean of all sample means will follow a normal distribution irrespective of the original distribution to which the data belonged to provided that
i) the samples are drawn at random
ii) The sample size should be atleast 30
Hence here we find that the correct conditions is a.
Only option a is right
a. The sample has more than 30 grade-point averages.