3. To determine whether chocolate or vanilla ice cream is more popular, the owner of the Zootie ice cream shop takes a random sample of vanilla and chocolate ice cream sales for several days. For the 14 days sampled, an average of 25 people bought vanilla and 30 people bought chocolate each day. The standard deviations were 1.9 and 2.3, respectively. The distribution of sales of both flavors is assumed to be normal, but the variances are unknown. For both a and b, use a significance level of 0.05. а) Determine whether there is statistical evidence that the variances in ice cream sales for vanilla and chocolate are equal. b) Based on your answer in part a, conduct an appropriate hypothesis test to determine if vanilla and chocolate differ in average daily sales.

Given a sample data set with a Variance of 12.25 and Mean of 4.0, what is the Coefficient of Variation of the data set.?

A parenting magazine reports that the average amount of wireless data used by teenagers each month is 5 Gb. For her science fair project, Ella sets out to prove the magazine wrong. She claims that the mean among teenagers in her area is less than reported. Ella collects information from a simple random sample of 25 teenagers at her high school, and calculates a mean of 4.7 Gb per month with a standard deviation of 0.9 Gb per month. Assume that the population distribution is approximately normal. Test Ella's claim at the 0.01 level of significance. Step 3 of 3: Draw a conclusion and interpret the decision. E Tables E Keypad Answer Keyboard Shortcuts We reject the null hypothesis and conclude that there is sufficient evidence at a 0.01 level of significance that the average amount of wireless data used by teenagers each month is less than 5 Gb. We fail to reject the null hypothesis and conclude that there is insufficient evidence at a 0.01 level of significance that the average amount of…

A college in the northeastern United States used SAT scores to help decide which applicants to admit. To determine whether the SAT was useful in predicting success, the college examined the relationship between the SAT scores and first-year GPAs of admitted students. The average math SAT score of a sample of 200 randomly selected students was 649.5 with a standard deviation of 66.2. The average GPA of the same students was 2.63 with a standard deviation of 0.58. The correlation between GPA and math SAT score was 0.19. (a) What does the correlation of 0.19 tell us about SAT scores and GPA scores? (You need to provide two answers.)(b) Find the equation of the least squares regression line.(c) Using the equation, predict the GPA score of a person with a math SAT score of 650.(d) Using the equation, predict the GPA score for a person with a math score of 800.

The salaries of professional baseball players are heavily skewed right with a mean of $3.2 million and a standard deviation of $2 million. The salaries of professional football players are also heavily skewed right with a mean of $1.9 million and a standard deviation of $1.5 million. A random sample of 40 baseball players’ salaries and 35 football players’ salaries is selected. The mean salary is determined for both samples. Let  represent the difference in the mean salaries for baseball and football players. Which of the following represents the shape of the sampling distribution for ? skewed right since the populations are both right skewed skewed right since the differences in salaries cannot be negative approximately Normal since both sample sizes are greater than 30 approximately Normal since the sum of the sample sizes is greater than 30

A parenting magazine reports that the average amount of wireless data used by teenagers each month is 10 Gb. For her science fair project, Ella sets out to prove the magazine wrong. She claims that the mean among teenagers in her area is less than reported. Ella collects information from a simple random sample of 16 teenagers at her high school, and calculates a mean of 9.1 Gb per month with a standard deviation of 1.3 Gb per month. Assume that the population distribution is approximately normal. Test Ella's claim at the 0.05 level of significance. Step 3 of 3: Draw a conclusion and interpret the decision.