Answer: 9/25 or 36%
Step-by-step explanation:
72 + 28 + 62 + 38 = 200
There are 200 people in total and 72 are youngsters who like sport cars.
So, the number of youngsters who like cars out of the total number of people is 72/200.
Now, find a greatest common divisor. In this case, the greatest common divisor is 8.
72 / 8 = 9
200 / 8 = 25
9/25 (fraction)
25 * 4 = 100
9 * 4 = 36
36/100 = 36% (percentage)
He had saved 320 initially
Step-by-step explanation:
Let the amount he saved be 'a'
Amount spent = 20 + 40 + 30
= 90
His grand father gave 50
At the end he has 280
280 = a - 90 +50
a = 280 -50 +90
= 320
He had saved 320 initially
Answer:
A sample of 1068 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is:
95% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
At 95% confidence, how large a sample should be taken to obtain a margin of error of 0.03 for the estimation of a population proportion?
We need a sample of n.
n is found when M = 0.03.
We have no prior estimate of , so we use the worst case scenario, which is 
Then
Rounding up
A sample of 1068 is needed.
Answer:
Step-by-step explanation:
Answer:
Total cost = charge fee + 55× no. of hours
Let h represents number of hours
Total cost = 35 + (55×h)
