To compare the effectiveness of two treatments, researchers conducted a well-designed experiment using a randomized block design in which the subjects were blocked by age-group (under 40 years and 40 years or older). Which of the following must be true about the randomized block design of the experiment? (A) The number of subjects in each block is different.
(B) Treatments are randomly assigned to subjects within each block.
(C) The design cannot have a control group because subjects are blocked by age-group.
(D) The experiment uses a matched-pairs design, where subjects from one block are paired with subjects from the other block.
(E) The subjects in one block receive one treatment, and the subjects in the other block receive the other treatment.

(B) Treatments are randomly assigned to subjects within each block.

Step-by-step explanation:

In the case when the comparison of the treatments should be done so the researcher want to conducted the experiment where the subjects were blocked by the age group so here the option b is considered as in this the treatments would be allocated on the randomly basis to the subject with respective to the each and every block

Rest of the options are wrong as the number of subjects are same, the design have the control and there is same replication of the number

walter needs to make at least 5 more cookies but no more than 40. 5 ≥ x ≥ 40;

step-by-step explanation:

walter has to make a minimum of 20 cookies. he already has 15 cookies made, so he must make 5 more to meet the minimum.

the maximum amount of cookies he can make is 55. he already has 15, so he has to make no more than 40 more cookies to meet the maximum.

linear pair postulates