Mathematics, 31.05.2021 14:30, wednesdayA

A psychiatrist is interested in finding a 90% confidence interval for the tics per hour exhibited by children with Tourette syndrome. The data below show the tics in an observed hour for 13 randomly selected children with Tourette syndrome. The population standard deviation is σ=4.08. Required:
a. To compute the confidence interval use a, z or t distribution?
b. With 90% confidence the population mean number of tics per hour that children with Tourette syndrome exhibit is between and .

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answered: shortyyashaun

a) z-distribution is used, as we have the standard deviation for the population.

b) Between $\overline{x} - 1.86$ and $\overline{x} + 1.86$ , in which $\overline{x}$ is the sample mean of tics per hour.

Step-by-step explanation:

a. To compute the confidence interval use a, z or t distribution?

We have the standard deviation for the population, and thus, the z-distribution is used.

b. With 90% confidence the population mean number of tics per hour that children with Tourette syndrome exhibit is between ______ and _______ .

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.9}{2} = 0.05$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$ .

That is z with a pvalue of 1 - 0.05 = 0.95 , so Z = 1.645.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 1.645\frac{4.08}{\sqrt{13}} = 1.86$

The lower end of the interval is the sample mean subtracted by M. So it is $\overline{x} - 1.86$

The upper end of the interval is the sample mean added to M. So it is $\overline{x} + 1.86$

Between $\overline{x} - 1.86$ and $\overline{x} + 1.86$ , in which $\overline{x}$ is the sample mean of tics per hour.

answered: Guest

step-by-step explanation:

What is the image of g for a dilation with a center (0,0) and a scale factor of 1? a. (-1,3) b. (1,

answered: Guest

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!