Answer:
We need to send more than 400 messages for Plan B to be the better option.
Step-by-step explanation:
Plan A
The cost is a flat fee of 30 plus 10 cents per message
Cost= 30 +.10m
Plan B
The cost is a flat fee of 50 plus 5 cents per message
Cost = 50 +.05m
We want cost of B to be less than cost A
30 +.10m > 50 +.05m
Subtract .05m from each side
30 +.10m- .05m > 50 +.05m-.05m
30 +.05m > 50
Subtract 30 from each side
30-30 +.05m > 50-30
.05m > 20
Divide each side by .05
.05/.05m > 20/.05
m > 400
We need to send more than 400 messages for Plan B to be the better option.
Answer: 1
Step-by-step explanation:
17 minus 2 = 15
16 minus 1 = 15
Answer:
$4.47
Step-by-step explanation:
Price if 1 pound of bananas=$1.49
Price if 3 pounds of bananas=3x$1.49
=$4.47
Answer:
The minimum sample size needed is 
. If n is a decimal number, it is rounded up to the next integer. 
is the standard deviation of the population.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Z-table as such z has a p-value of 
.
That is z with a pvalue of 
, so Z = 1.645.
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
How large a sample must she select if she desires to be 90% confident that her estimate is within 4 ounces of the true mean?
A sample of n is needed, and n is found when M = 4. So
The minimum sample size needed is . If n is a decimal number, it is rounded up to the next integer. is the standard deviation of the population.
Answer:
45
Step-by-step explanation:
