Statistics Questions & Answers

3. Box and Whisker Plot: Draw a box and whisker plot for the data provided and identify any outliers. \( 12,17,13,14,12,16,18,29,15,14,12,17,13,14,12,16,18,29,15,14,12,17,13 \), \( 14,12,16,18,29,15,14 \)

2. Scatter Plot and Correlation: Consider the following data points representing the number of hours studied \( (x) \) and the marks obtained \( (y) \) : \[ (1,50),(2,55),(3,60),(4,65),(5,75) \] wa scatter plot and determine whether the relationship between hours studied and marks ositive, negative, or none.

What does the magnitude of a correlation coefficient indicate about the variables in a correlational study? Multiple Choice strength of the variables relationship between the variables number of data points

20. Some researchers claim that herbal supplements such as ginseng or ginkgo biloba enhance human memory. To test this claim, a researcher selects a sample of \( n=25 \) college students. Each student is given a ginkgo biloba supplement daily for 6 weeks and then all of the participants are given a standardized memory test. Scores on the normalized test are \( \mu=70 \) and standard deviation of 15 . The sample of 25 students had a mean score of \( M=75 \). (8 points) a. Do the data indicate a significant effect of the herb on memory? Use a two-tailed test with \( \alpha=0.05 \). (Show all steps.)

You wish to test the following claim \( \left(H_{a}\right) \) at a significance level of \( \alpha=0.002 \). \[ \begin{array}{l}H_{a}: \mu_{1}=\mu_{2} \\ H_{a}: \mu_{1}>\mu_{2}\end{array} \] You believe both populations are normally distributed, but you do not know the standard deviations for either. However, you also have no reason to believe the variances of the two populations are not equal. You obtain a sample of size \( n_{1}=20 \) with a mean of \( M_{1}=51.3 \) and a standard deviation of \( S D_{1}=13.2 \) from the first population. You obtain a sample of size \( n_{2}=23 \) with a mean of \( M_{2}=38.8 \) and a standard deviation of \( S D_{2}=8.7 \) from the second population.

De una muestra aleatoria de 1.203 estudiantes de contaduría de cierto año, el \( 20,2 \% \) afirı que la oferta laboral era muy mal pagada. De una muestra aleatoria de 1.203 estudian de empresariales en otro año posterior, el \( 13,2 \% \) compartían dicha opinión. Calcule un tervalo de confianza del \( 99 \% \) para la diferencia entre las proporciones poblacionales.

g) Of the " \( r \) " values below which would be reasonable for the scatterplot above? Explai your reasoning. \( r=-.94 \quad r=-.32 \quad r=.32 \quad r=.94 \)

Step 4: Determine citical Value Twot aided test \( \bar{w} \) a \( =0.05 \) and \( n-1=15 \) (df Use + distrubution table \( = \pm 2.131 \)

3) Find the missing \( z \)-number: \( \mathrm{p}(z<c)=0.7 \). You must sketch, shade, and label a bell curve for credit. 4) Out of 400 people surveyed, 181 answered 'yes' to having a Netflix account. Find the margin of error

2) Compute: \( \mathrm{p}(0.8<z<2.19) \). You must sketch, shade, and label a bell curve for credit. 3) Find the missing z-number: \( \mathrm{p}(\mathrm{z}<\mathrm{c})=0.7 \). You must sketch, shade, and label a bell curve for credit.