MTH 240-41H Samantha Wallace 12a/17 8:23 PM Homework: Homework 9.2 Save Score: 0

Question

MTH 240-41H Samantha Wallace 12a/17 8:23 PM Homework: Homework 9.2 Save Score: 0.33 of 1 pt 90f 18 (7 complete) Hw Score: 31.02%, 5.58 of 18 pts 9.2.29 -Question Help * A researcher wishes to estimate the randomly selects records from 900 such drivers in 2009 and determines the sample mean BAC to be 0.16 gldL with a standard deviation of 0.07 g/dL. Complete parts (a) through (d) below. a) A nisiogram or DiooG aiconoi concenuauons in rauai accioents snows tnat bALs are nignny skewea rign. Expain wry a arge sampie size is needec to construct a blood alcohol concentration (BAC) for drivers involved in fatal who are found to have positive BAC values. He confidence interval for the mean BAC of fatal crashes with a positive BAC. OA. Since the distribution of blood alcohol concentrations is not normally distributed (highly skewed right), the sample mean will be approximately normal 85% regardless of sample size. O B. Since the distribution of blood alcohol concentrations is normally distributed, the sample mean ill be approximately normal regardless of sample size. O C. Since the distribution of blood alcohol concentrations is normally distributed, the sample must be large so that the distribution of the sample mean will be normal. D. Since the distribution of blood alcohol concentrations is not normally distributed (highly skewedight), the sample must be large so that the distribution of the sample mean will be normal. (b) In 2009, there were approximately 25,000 fatal crashes in which the driver had a positive BAC. Explain why this, along with the fact that the data were obtained using a simpl e random sample, satisfies the requirements for constructing a confidence interval O A. The sample size is greater than 10% of the population. B. ° C. , b, The sample size is less than 10% of the population. The sample size is greater than 5% of the population. The sample size is less than 5% of the population BAC in fatal crashes in which the dmer had a positive BAC. (c) Determine and interpret a 90% confidence interval for the mean The 90% confidence interval for the mean BAC is (Round to the nearest thousandth as needed.) Enter your answer in the edit fields and then click Check Answer. Clear All 2

Explanation / Answer

The Confidence Interval formula is

X ± Z

s

(n)

Where:

Z

80%

1.282

85%

1.440

90%

1.645

95%

1.960

99%

2.576

99.5%

2.807

99.9%

3.291

Here, X = .16 g/dL

Confidence interval for 90%. Thus, Z = 1.645

S= .09 g/dL

n = 900

Thus, Confidence interval

= .16 ± 1.645 (.07/Sq.Rt(900))

= ,16 ± .0038

= ( 0.1561 to 0.1638)

X ± Z

s

(n)

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.