Answer:
B
Step-by-step explanation:
The closed circle at -
indicates that x can equal this value
The open circle at
indicates that x cannot equal this value.
All values of x between -
and
are valid, thus
-
≤ x <
→ B
Answer:
a. 19.68 miles per gallon.
b. 26.32 miles per gallon.
Step-by-step explanation:
Mean gas mileage (μ) = 23.0 mpg
Standard deviation (σ) = 4.9 mpg
In a normal distribution, for any length X, the z-score is determined by the following expression:

In a normal distribution, the 25th percentile (first quartile) of a normal distribution has a corresponding z-score of z = -0.677 and the 75th percentile has a corresponding z-score of z = 0.677
a. The first quartile of the distribution of gas mileage is

19.68 miles per gallon.
b. The third quartile of the distribution of gas mileage is

26.32 miles per gallon.
Answer:
C. Biased, because she only asked students on honor roll.
Step-by-step explanation:
Since Mrs. Gilbert's goal was to find how many students that spent >4 hours and not how many students that earned Honor Roll that spent >4 hours, the data is biased. Choose C.
Answer:
The total amount a member pays for an item with a regular price of x dollars is T (x) = 0.963<em>x</em>.
Step-by-step explanation:
Key points:
- Discount is subtracted from the regular price of an item.
- Sales tax is added to the regular price of an item.
It is provided that the customers receive a 10% discount if they are members and all customers must pay 7% in sales tax.
Two functions are provided are:
f (x) = 0.90<em>x </em>; the price of an item after the 10% member discount
g (x) = 1.07<em>x </em>; the total amount customers pay for a purchase after sales tax is applied.
Compute the total amount a member pays for an item with a regular price of x dollars as follows:
T (x) = Discount × Sales Tax
= 0.90 × 1.07 × <em>x</em>
= 0.963<em>x</em>.
Thus, the total amount a member pays for an item with a regular price of x dollars is T (x) = 0.963<em>x</em>.