<span>Slope is calculate by dividing the change in y-values by the change in x-values between a pair of points. For 7: (7-1)/(1-10) = 6/-9 = -2/3 For 8: (6.1-3.1)/(-5.5 - -2.5) = 3/-3 = -1 For 9: (5/2 - -3) / (-5 - -7/3) = 11/2 / -8/3 = -33/16. This is not an answer option, so double check the problem.</span>

8 0

2 years ago

Read 2 more answers

50 random teenagers were asked how many hours a day they use their phone. They spent an average of 7 hours a day with a standard

tatyana61 [14]

Answer:

The margin of error for the true mean number of hours a teenager spends on their phone is of 0.4 hours a day.

Step-by-step explanation:

We have the standard deviation of the saple, so we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 50 - 1 = 49

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 49 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.95}{2} = 0.975$ . So we have T = 2

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2\frac{1.3}{\sqrt{50}} = 0.4$

In which s is the standard deviation of the sample and n is the size of the sample.

The margin of error for the true mean number of hours a teenager spends on their phone is of 0.4 hours a day.

4 0

2 years ago

Evaluate the expression

Ivenika [448]

Answer:

Step-by-step explanation:

8 0

2 years ago