Check Your Understanding 10.1 and 12.2

A car part company uses two suppliers. They feel that supplier A is producing less than B. The sample data gathered 10 days worth from both companies. Assume the a normal distribution. Use the data in the image for reference.

We want to test at the 5% significance level under the assumption that the population variances are equal.

Which test stat will you use to solve this hypothesis test?

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A car part company uses two suppliers. They feel that supplier A is producing less than B. The sample data gathered 10 days worth from both companies. Assume the a normal distribution. Use the data in the image for reference.

We want to test at the 5% significance level under the assumption that the population variances are equal.

Find the pooled variance.

A car part company uses two suppliers. They feel that supplier A is producing less than B. The sample data gathered 10 days worth from both companies. Assume the a normal distribution. Use the data in the image for reference.

We want to test at the 5% significance level under the assumption that the population variances are equal.

What is the test stat?

round to 3 decimals

A car part company uses two suppliers. They feel that supplier A is producing less than B. The sample data gathered 10 days worth from both companies. Assume the a normal distribution. Use the data in the image for reference.

We want to test at the 5% significance level under the assumption that the population variances are equal.

What is the conclusion?

• We cannot conclude that u1 is less than u2. (Do not reject the null)

• We can conclude that u1 is less than u2. (Reject the null)

The expected number of Government Professional that slept on the job is:

• 235

• 176

• 124

• 165

The expected numbers for each cell are the following: 235, 176, 124 and 165.

Do these expected frequencies(values) make the chi-square test valid, why or why not?

• No, the expected values are greater than 5.

• Yes, the expected values are greater than 5.

• Not enough information

For the chi square test of independence, the assumed degrees of freedom are:

• 1

• 2

• 3

• 4

At 5% significance level, the critical value is:

• 5.991

• 0.004

• 3.841

• 5.024

Consider the following data drawn independently from normally distributed populations:

Construct the 95% confidence interval for the difference between the population means.

What formula will you use?

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Consider the following data drawn independently from normally distributed populations:

Construct the 95% confidence interval for the difference between the population means.

What is the Za/2?

• 1.645

• 1.96

• 2.33

• .05