Question

You collect a random sample of 50 children and compute , the average height in inches. The sample standard deviation (s) equals 10. Suppose the true mean height μ equals 45 inches. For which of the following values of will a 95% confidence interval contain the true mean μ? I. = 47.5 inches II. = 50 inches III. = 42 inches

123

likes
613 views

Answer to a math question You collect a random sample of 50 children and compute , the average height in inches. The sample standard deviation (s) equals 10. Suppose the true mean height μ equals 45 inches. For which of the following values of will a 95% confidence interval contain the true mean μ? I. = 47.5 inches II. = 50 inches III. = 42 inches

Expert avatar
Birdie
4.5
104 Answers
We can use the formula for a confidence interval:

Confidence Interval = \bar{x} \pm z \times \frac{s}{\sqrt{n}},

where:
\bar{x} is the sample mean,
z is the Z-value for the desired confidence level (95% in this case),
s is the sample standard deviation,
n is the sample size.

Given values:
\bar{x} = \mu = 45 inches,
s = 10 inches,
n = 50 children,
For 95% confidence level, the Z-value is 1.96 (you can refer to Z-table for this value).

Plugging in these values we get:

I. CI_{I} = 47.5 \pm 1.96 \times \frac{10}{\sqrt{50}},

II. CI_{II} = 50 \pm 1.96 \times \frac{10}{\sqrt{50}},

III. CI_{III} = 42 \pm 1.96 \times \frac{10}{\sqrt{50}}.

Calculating these confidence intervals gives:

I. CI_{I} = 47.5 \pm 2.78,
II. CI_{II} = 50 \pm 2.78,
III. CI_{III} = 42 \pm 2.78.

Only the 95% confidence interval for I. contains the true mean height 45 inches.

\boxed{\text{Answer: I. } \mu = 47.5 \text{ inches}}

Frequently asked questions (FAQs)
Question: What is the result of dividing 3/4 by 2/5?
+
What is the measure of an angle formed by two intersecting lines, if one angle measures 120 degrees?
+
Math Question: Find the length of side c in a triangle, with side a = 10, side b = 15, and angle C = 60° using the Sine Law.
+
New questions in Mathematics
-442/c+5=26 what is c?
two pails of different sizes contain 34.5 litres of water altogether When 0.68 litre of water is poured from the bigger pail into the smaller pail the amount of water in the bigger pail is 9 times that in the smaller pail. How much water was in the smaller pail at first?
The length and breadth of my rectangular vegetable garden is 12,5m and 7,25m respectively. What is the perimeter of the garden?
Elliot opened a savings account and deposited $5000.00 as principal. The account earns 4% interest, compounded annually. How much interest will he earn after 5 years? Round your answer to the nearest cent.
Log(45)
What is the appropriate measurement for the weight of an African elephant?
∫ √9x + 1 dx
19) If the temperature of -8°C decreases by 12°C, how much will it be? a)-20°C -4°C c) 4°C d) 20°C
DuocUC 2) The cost C, in pesos, for the production of x meters of a certain fabric can be calculated through the function: (x+185) C(x)=81300-6x+ 20000 a) It is known that C(90) 5.344. Interpret this result. (2 points) b) Calculate C'(x) (2 points) 3 x²+111x-0.87 20000 2000 c) Function C calculates the cost while producing a maximum of 500 meters of fabric. Determine the values of x at which the cost of production is increasing and the values of x at which the cost is decreasing. (3 points) d) If a maximum of 500 meters of fabric are produced, what is the minimum production cost? (
Quadratic equation 2X = 15/X + 7
A popular cell phone family plan provides 1500 minutes. It charges 89.99/month for the first 2 lines and 9.99 for every line after that. Unlimited text messages for all phone lines costs $30.00/month, and Internet costs $10.00/month per phone line. If a family with a $200 monthly budget buys this plan and signs up for unlimited text messaging and Internet on each phone line, how many cell phone lines can they afford? Use an inequality to solve this problem. Graph your solution on the number line and explain the meaning of your graph in a sentence.
2X+2=8
What js the greatest 4-digit even number that can be formed by 3,6,1,4?
16-(x²+x+2)²
The slope of the tangent line to the curve f(x)=4tan x at the point (π/4,4)
The perimeter of a rectangular rug is 42 feet. The width is 9 feet. What is the length?
5a-3.(a-7)=-3
If the area of a circle is 75.7ft2, what is the radius? Give the answer in metres. Round answer to 2 decimal places and enter the units.
Find the rule that connects the first number to the second number of each pair. Apply the rule to find the missing number in the third pair. (18 is to 22) (54 is to 26) (9 is to ?)
The domain of the function f(x)=x+7x2−144 is (−∞,), ( ,), and ( , ∞).