Mixed Confidence Intervals Quiz

Use the z table or your calculator to find the critical value that corresponds to 92% confidence.

• 1.41

• 1.75

• 1.81

• 1.96

Tags

CCSS.HSS.ID.A.4

Use the t table to find the critical value.

96% confident, df = 10

• 2.36

• 2.76

• 1.95

• 2.40

Use the t table to find the critical value.

95% confident, sample size = 8

• 2.36

• 2.31

• 1.89

• 1.86

Choose the appropriate confidence interval for the situation:

A random sample of 30 movie theaters showed that the average price for a movie was $10 with a standard deviation of $1.20.

• z confidence interval for a mean

• t confidence interval for a mean

• z confidence interval for a proportion

• t confidence interval for a proportion

Tags

CCSS.HSS.ID.A.4

Compute a 90% confidence interval for the situation:

A random sample of 30 movie theaters showed that the average price for a movie was $10 with a standard deviation of $1.20.

• (9.71, 10.29)

• (9.934, 10.066)

• (9.64, 10.36)

• (9.628, 10.372)

Tags

CCSS.HSS.IC.B.4

Choose the appropriate confidence interval for the situation:

After watching a horror film, 34 out of 50 people reported problems getting to sleep.

• z confidence interval for a mean

• t confidence interval for a mean

• z confidence interval for a proportion

• t confidence interval for a proportion

Compute a 95% confidence interval:

After watching a horror film, 34 out of 50 people reported problems getting to sleep.

• (.55, .81)

• (.571, .789)

• (.671, .689)

• There is not enough information to compute a confidence interval.

Tags

CCSS.HSS.IC.B.4

Compute a 98% confidence interval:

Last year, the times for Midlo soccer games were normally distributed with a standard deviation of 2.8 minutes. A random sample of 7 soccer games this year had an average length of 94 minutes.

• (91.235, 96.765)

• (91.827, 96.173)

• (91.538, 96.462)

• (90.674, 97.326)

Tags

CCSS.HSS.IC.B.4

Decide if the distribution is normal:

In a sample of 28 students, 85% said they like horror movies.

• No, because n < 30

• Yes, because np > 10

• No, because nq < 10

• Yes because the population is normal

Decide if the distribution is normal:

SAT scores are normally distributed with a standard deviation of 180. A random sample of 28 Midlo students had an average score of 1120.

• No, because n < 30

• Yes, because np and nq are both ≥ 10

• No, because nq < 10

• Yes because the population is normal