Answer:
x=4
Step-by-step explanation:
<em>Multiply by 2 from both sides of equation.</em>
<em>2x/7-5=2*2</em>
<em>Simplify, to find the answer.</em>
<em>2*2=4</em>
<em>x=4 is the correct answer.</em>
<em>I hope this helps you, and have a wonderful day! </em>
Answer:


Step-by-step explanation:
Given

Solving (a): The mean of the 6 samples.
This is calculated as:

So, we have:



Solving (b): The sample standard deviation.
This is calculated using:

So, we have:






follows from the fact that the cosine function is

-periodic, which means

. Roughly speaking, this is the same as saying that a point on a circle is the same as the point you get by completing a full revolution around the circle (i.e. add

to the original point's angle with respect to the horizontal axis).
If you make another complete revolution (so we're effectively adding

) we get the same result:

. This is true for any number of complete revolutions, so that this pattern holds for any even multiple of

added to the argument. Therefore

for any integer

.
Next, because

, it follows that

is also true for any integer

. So we have

The rest follows from considering either case and solving for

.
Hope this helps you good luck
Answer: 3 bottles of sunscreen- $22.5,
2 beach towels- $30
and 3 floats- $30.75
Step-by-step explanation: