Answer:
B
Step-by-step explanation:
2x-3=7
Add 3 to both sides:
2x=10
Divide both sides by 2:
x=5
Hope this helps!
Answer:
The minimum number of cities we need to contact is 96.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence interval
, 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 interval
So
, z is the value of Z that has a pvalue of
, so
.
In this problem, we have that:







The minimum number of cities we need to contact is 96.
Answer:
1456
Step-by-step explanation:
56x2x13
56x26
1456
Answer:
Option B
Step-by-step explanation:
Since, number of calories 'C' burned is proportional to the number of minutes (m) given to the exercise,
C ∝ m
C = km
Where k is the proportionality constant.
From the table attached,
For C = 250 calories and m = 30 minutes,
250 = 30k
k = 
= 
Therefore, equation representing this situation will be,
C = 
Option B will be the correct option.