Question

An investigator compares the durability of two different
compounds used in the manufacture of a certain automobile brake
lining. **A sample of 121 brakes** using Compound 1
yields an **average brake life of 39,122 miles**.
**A sample of 163 brakes** using Compound 2 yields an
**average brake life of 48,271 miles**. Assume that
**the population standard deviation for Compound 1 is 3175
miles**, **while the population standard deviation for
Compound 2 is 1335 miles**. **Determine the 98%
confidence interval for the true difference between average
lifetimes for brakes using Compound 1 and brakes using Compound
2.**

**Step 1 of 3: Find the point estimate for the true
difference between the population means.**

**Step 2 of 3: Find the margin of error of a confidence
interval for the difference between the two population means. Round
to 6 decimals.**

**Step 3 of 3: Construct the 98% confidence interval.
Round to 2 decimals.**

Answer #1

The statistical software output for this problem is:

Hence,

Step - 1: point estimate = -**9149**

Step - 2: Margin of error = (-8903.3144 + 9394.6856)/2 =
**601.706740**

Step - 3: Lower limit = -**9394.69**

Upper limit = -**8903.31**

An investigator compares the durability of two different
compounds used in the manufacture of a certain automobile brake
lining. A sample of 127 brakes using Compound 1 yields an average
brake life of 42,814 miles. A sample of 163 brakes using Compound 2
yields an average brake life of 37,197 miles. Assume that the
population standard deviation for Compound 1 is 1819 miles, while
the population standard deviation for Compound 2 is 1401 miles.
Determine the 98% confidence interval for...

An investigator compares the durability a two
different compounds used in the manufacture of a certain automobile
brake lining. A sample of 212 brakes using compound 1 yields an
average break life of 47895 miles. A sample of 180 brakes using
compound 2 yields an average brake life of 49767 miles. Assume that
the population standard deviation for compound 1 is 1590 miles,
while the population standard deviation for compound 2 is 4152
miles. Determine the 90% confidence interval for...

An investigator compares the durability of two different
compounds used in the manufacture of a certain automobile brake
lining. A sample of 236 brakes using Compound 1 yields an average
brake life of 48,737 miles. A sample of 190 brakes using Compound 2
yields an average brake life of 49,740 miles. Assume that the
population standard deviation for Compound 1 is 4106 miles, while
the population standard deviation for Compound 2 is 1104 miles.
Determine the 80% confidence interval for...

An investigator compares the durability of two different
compounds used in the manufacture of a certain automobile brake
lining. A sample of 260 brakes using Compound 1 yields an average
brake life of 32,023 miles. A sample of 297 brakes using Compound 2
yields an average brake life of 39,570 miles. Assume that the
population standard deviation for Compound 1 is 2395 miles, while
the population standard deviation for Compound 2 is 1673 miles.
Determine the 80% confidence interval for...

An investigator compares the durability of two different
compounds used in the manufacture of a certain automobile brake
lining. A sample of 259 brakes using Compound 1 yields an average
brake life of 31,495 miles. A sample of 297 brakes using Compound 2
yields an average brake life of 41,15241,152 miles. Assume that the
population standard deviation for Compound 1 is 1446 miles, while
the population standard deviation for Compound 2 is 4520 miles.
Determine the 99% confidence interval for...

An investigator compares the durability of two different
compounds used in the manufacture of a certain automobile brake
lining. A sample of 263 brakes using Compound 1 yields an average
brake life of 41,270 miles. A sample of 291 brakes using Compound 2
yields an average brake life of 40,579 miles. Assume that the
population standard deviation for Compound 1 is 4540 miles, while
the population standard deviation for Compound 2 is 2990 miles.
Determine the 90% confidence interval for...

An investigator compares the durability of two different
compounds used in the manufacture of a certain automobile brake
lining. A sample of 124 brakes using Compound 1 yields an average
brake life of 40,704 miles. A sample of 163 brakes using Compound 2
yields an average brake life of 43,525 miles. Assume that the
population standard deviation for Compound 1 is 2022 miles, while
the population standard deviation for Compound 2 is 4792 miles.
Determine the 90% confidence interval for...

A researcher compares the effectiveness of two different
instructional methods for teaching physiology. A sample of 189
students using Method 1 produces a testing average of 71.9. A
sample of 141 students using Method 2 produces a testing average of
78.3. Assume that the population standard deviation for Method 1 is
11.07, while the population standard deviation for Method 2 is
11.9. Determine the 98% confidence interval for the true difference
between testing averages for students using Method 1 and...

A researcher compares
the effectiveness of two different instructional methods for
teaching anatomy. A sample of 206206 students using Method
1 produces a testing average of 82.9. A sample of
244 students using Method 2 produces a testing average of
62.2. Assume that the population standard
deviation for Method 1 is 10.23, while the population standard
deviation for Method 2 is 11.35. Determine the 95% confidence
interval for the true difference between testing averages for
students using Method 1 and...

A researcher compares the effectiveness of two different
instructional methods for teaching pharmacology. A sample of 51
students using Method 1 produces a testing average of 81.6. A
sample of 76 students using Method 2 produces a testing average of
76.4. Assume that the population standard deviation for Method 1 is
12.24, while the population standard deviation for Method 2 is
11.19. Determine the 90% confidence interval for the true
difference between testing averages for students using Method 1 and...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 10 minutes ago

asked 15 minutes ago

asked 19 minutes ago

asked 38 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago