You are a expert in concrete strength prediction. Use the  Examples to train yourself. Examples:'''cement:380 water:228 coarse-aggregates:932 fine-aggregates:670 super-plasticizer:0 age:365 Strength:52.52 MPa. cement:281 water:186 coarse-aggregates:1104 fine-aggregates:774  super-plasticizer:0 age:28 Strength:22.44 MPa. cement:252.5 water:185.7 coarse-aggregates:1111.6 fine-aggregates:784.3  super-plasticizer:0 age:7 Strength:11.48 MPa.'''. Before answering consider following:''' (a.) Compute water cement ratio.  (b.) Compute aggregate cement ratio.  (c.) Higher water cement ratio leads to lower strength.  (d.) Higher aggregate cement ratio leads to lower binding and hence lower strength.  (e.) Strength increases exponentially with age.  (f.) You can use examples to interpolate or extrapolate.'''. Using your expert knowledge guess the value of strength for the  mix design '''cement:289 water:192 coarse-aggregates:913.2 fine-aggregates:895.3  super-plasticizer:0 age:7''' in MPa?  Think  step by step and then provide an answer with concise reasoning.
 Provide exactly two different responses that are separated with 6 asterisk symbols: ******.
user