Scientists collect data on the blood cholesterol levels (milligrams per deciliter of blood) of a random sample of 24 laboratory rats. A 95% confidence interval for the mean blood cholesterol level μ is 80.2 to 89.8. Which of the following would cause the most worry about the validity of this interval?

(a) There is a clear outlier in the data.
(b) A stemplot of the data shows a mild right skew.
(c) You do not know the population standard deviationσ.
(d) The population distribution is not exactly Normal.
(e) None of these are a problem when using a t interval.

(a) There is a clear outlier in the data.

Step-by-step explanation:

The statement relates that sample= 24

Confidence interval= 80.2 to 89.8.

Now the data does not mention anywhere the standard deviation which is an important parameter in using the t-procedure rather we assume that standard deviation is not known. So, the most worrying part is the skewness and the presence of strong outliers in the t-procedure.

So, the option a) is correct meaning a clear outlier in the data.

x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

step-by-step explanation:

last month maria hiked the 5-mile mountain trail a number of times and she hiked the 10-mile canal trail several times. let x represent the number of times she hiked the 5-mile trail, and let y represent the number of times she hiked the 10-mile trail. if she hiked a total of 90 miles, which equation can be used to find the number of times maria hiked each trail? x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,