Answer:
140 individuals were surveyed
42 people are planning on going to the mountains
Step-by-step explanation:
The question is missing the information regarding the percentage of people who said that they were going to each of the possible destinations. After a quick google search I've found that, in the original question, 32% of individuals were going to the beach, 15% to the desert, 23% to major cities, and 30% to the mountains.
If 21 people said they were going to the desert, and that corresponds to 15% of the total number of people surveyed, the number of people surveyed is:

140 individuals were surveyed
Since 30% responded "the mountains", the number of people planning on going to the mountains is:

42 people are planning on going to the mountains
Answer: circumference = 2Πr²
Where r= 3
Π=3.14
Therefore Circumference = 2×3.14× 3²
= 2×28.26
Circumference=56.52
Formula:
Subtitute in 3 for r.
Solve and the answer is 28.26
Answer: the value of population standard deviation is 3.87
Step-by-step explanation:
From the information given,
Number of sample, n = 8
For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
Since confidence interval = 2.694,
It becomes
2.694 = 1.96 × standard deviation/√8
Dividing both sides of the equation by 1.96, it becomes
1.37 = standard deviation/√8
Standard deviation = 1.37 × √8
Standard deviation = 3.87