Correct answer is third option ---C in edge
Answer:
Step-by-step explanation:
We want to determine a 90% confidence interval for the true population mean textbook weight.
Number of sample, n = 22
Mean, u = 64 ounces
Standard deviation, s = 5.1 ounces
For a confidence level of 90%, the corresponding z value is 1.645. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
It becomes
64 ± 1.645 × 5.1/√22
= 64 ± 1.645 × 1.087
= 64 ± 1.788
The lower end of the confidence interval is 64 - 1.788 = 62.21 ounces
The upper end of the confidence interval is 64 + 1.788 = 65.79 ounces
Therefore, with 90% confidence interval, the true population mean textbook weight is between 62.21 ounces and 65.79 ounces
<span>46 square inches
If you look at the figure in the diagram, you'll see that it consist of two rectangles next to each other. So the area of the entire figure is the sum of the area of both rectangles. The leftmost rectangle is 5 inches by 6 inches for an area of 30 square inches. The right triangle is a skinny rectangle that is 8 inches by 2 inches for an area of 16 square inches. And 30 square inches plus 16 square inches equals 46 square inches.
An alternate way of considering the problem is that it's one large rectangle that's (5+8 = 13) inches long and 6 inches tall equaling 78 square inches, minus 2 other rectangles, both of which are 2 inches by 8 inches for an area of 16 square inches. And finally 78 square inches minus 16 square inches minus 16 square inches equals 46 square inches.</span>
