5*4 is 20 because 5+5+5+5 is 20
Answer:
At most 38 text messages.
Step-by-step explanation:
Let x represent number of text message you send or receive.
We have been given that the cell phone plan charges $.13 for each text message you send or receive. So amount charged for sending or receiving x text messages would be
.
We are also told that your cell phone plan cost $39.99 per month, so total cost of monthly bill would be
.
Since you can spend at most $45, so total cost of x messages should be less than or equal to 45 as:





Therefore, you can send or receive at most 38 text messages.
Answer:
Standard deviation of the sample = 17.421
Step-by-step explanation:
We are given that in a random sample of 80 teenagers, the average number of texts handled in one day is 50.
Also, the 96% confidence interval for the mean number of texts handled by teens daily is given as 46 to 54.
So, sample mean,
= 50 and Sample size, n = 80
Let sample standard deviation be s.
96% confidence interval for the mean number of texts,
is given by ;
96% confidence interval for
=
[46 , 54] =
Since lower bound of confidence interval = 46
So, 46 =
50 - 46 =
s =
= 17.421
Therefore, standard deviation of the sample is 17.421 .